database/openGauss-server
2
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
3c83075609c4fba836840f160306658bf568ff1b
openGauss-server/src/gausskernel/optimizer/plan/subselect.cpp
wangfeihuo dfb53df307 修复pullup导致的core问题
2024-09-26 19:13:24 +08:00

7511 lines
268 KiB
C++
Raw Blame History

/* -------------------------------------------------------------------------
*
* subselect.cpp
* Planning routines for subselects and parameters.
*
* Portions Copyright (c) 2020 Huawei Technologies Co.,Ltd.
* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/gausskernel/optimizer/plan/subselect.cpp
*
* -------------------------------------------------------------------------
*/
#include "postgres.h"
#include "knl/knl_variable.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/clauses.h"
#include "optimizer/cost.h"
#include "optimizer/pathnode.h"
#include "optimizer/pgxcship.h"
#include "optimizer/planmain.h"
#include "optimizer/planner.h"
#include "optimizer/prep.h"
#include "optimizer/randomplan.h"
#include "optimizer/subselect.h"
#include "optimizer/tlist.h"
#include "optimizer/var.h"
#include "parser/parse_relation.h"
#include "parser/parse_oper.h"
#include "parser/parsetree.h"
#include "parser/parse_hint.h"
#include "rewrite/rewriteManip.h"
#include "utils/builtins.h"
#include "utils/guc.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
#ifdef PGXC
#include "pgxc/pgxc.h"
#endif
#ifdef STREAMPLAN
#include "optimizer/streamplan.h"
#endif
#include "parser/parse_agg.h"
extern void set_path_seed_factor_zero();
typedef struct convert_testexpr_context {
PlannerInfo* root;
List* subst_nodes; /* Nodes to substitute for Params */
} convert_testexpr_context;
typedef struct process_sublinks_context {
PlannerInfo* root;
bool isTopQual;
} process_sublinks_context;
typedef struct finalize_primnode_context {
PlannerInfo* root;
Bitmapset* paramids; /* Non-local PARAM_EXEC paramids found */
} finalize_primnode_context;
typedef struct varWalkerContext {
int maxLevelsUp; /* Keep level up of var */
} varWalkerContext;
typedef struct pull_node_clause
{
List *nodeList;
List *nameList;
char *name;
bool recurse;
int flag;
} pull_node_clause;
typedef struct push_qual_context {
int varno; /* Var no. */
List* qual_list; /* Find qual list. */
} push_qual_context;
/*
* WinmagicContext
* context of winmagic optimization.
*/
typedef struct {
/* winmagic intermediate components */
List* pullup_tlist; /* the targetlist for new query (rewritten query) */
List* subquery_tlist; /* the targetlist for new subquery (from original query) */
Index resno; /* resno tracker */
Index winresno; /* resno of winagg */
List* outer_vars; /* vars from new query (rewritten query) */
List* inner_vars; /* vars from new subquery (from original query) */
WindowClause* winclause; /* winagg clause */
/* saved components of old sublink */
List* orig_target_vars; /* vars from original sublink's targetlist */
List* orig_qual_vars; /* vars from original sublink's qual */
TargetEntry* subtle; /* subquery's expression targetlist entry */
/* lambda wrappers */
List* (*pull_varlist)(List*, Node*);
Node* (*replace_nodes)(Node*, Node*, Node*);
} WinmagicContext;
#define WITH_TWO_ARGS (2)
/* flags bits for pull_expr_walker and pull expr_mutator */
#define PE_OPEXPR 0x01 /* pull expr of op expr */
#define PE_NULLTEST 0x02 /* pull expr of null test */
#define PE_NOTCLAUSE 0x04 /* pull expr of not clause */
#define PE_AGGREF 0x08 /* pull expr of sort group ref */
static Node* build_subplan(PlannerInfo* root, Plan* plan, PlannerInfo* subroot, List* plan_params,
SubLinkType subLinkType, Node* testexpr, bool adjust_testexpr, bool unknownEqFalse);
static List* generate_subquery_params(PlannerInfo* root, List* tlist, List** paramIds);
static List* generate_subquery_vars(PlannerInfo* root, List* tlist, Index varno);
static Node* convert_testexpr(PlannerInfo* root, Node* testexpr, List* subst_nodes);
static Node* convert_testexpr_mutator(Node* node, convert_testexpr_context* context);
static bool subplan_is_hashable(Plan* plan);
static bool testexpr_is_hashable(Node* testexpr);
static bool hash_ok_operator(OpExpr* expr);
static bool simplify_EXISTS_query(PlannerInfo* root, Query* query);
static Query* convert_EXISTS_to_ANY(PlannerInfo* root, Query* subselect, Node** testexpr, List** paramIds);
static Node* replace_correlation_vars_mutator(Node* node, PlannerInfo* root);
static Node* process_sublinks_mutator(Node* node, process_sublinks_context* context);
static Bitmapset* finalize_plan(PlannerInfo* root, Plan* plan, Bitmapset* valid_params, Bitmapset* scan_params);
static bool finalize_primnode(Node* node, finalize_primnode_context* context);
static Node* convert_joinqual_to_antiqual(Node* node, Query* parse);
static Node* convert_opexpr_to_boolexpr_for_antijoin(Node* node, Query* parse);
static bool get_equal_operates(OpExpr* qual, List** pullUpQual, bool paramAllowed);
static bool equal_expr(Node* node);
static bool has_correlation_in_rte(List* rtable);
static bool safe_convert_EXPR(PlannerInfo *root, Node *clause, SubLink* sublink, Relids available_rels, bool in_or_clause = false);
static void append_target_and_group(PlannerInfo *root, Query* subQuery, Node* node);
static bool get_pullUp_equal_expr(Node* node, List** pullUpQual, bool paramAllowed = true);
static bool pull_sublink_clause_walker(Node* node, pull_node_clause* context);
static bool safe_convert_EXISTS(PlannerInfo *root, SubLink* sublink, Relids available_rels);
static bool safe_convert_ANY(PlannerInfo *root, SubLink* sublink, Relids available_rels);
static bool safe_convert_ORCLAUSE(PlannerInfo *root, Node *clause, SubLink* sublink, Relids available_rels);
static bool finalize_agg_primnode(Node* node, finalize_primnode_context* context);
static Var* locate_base_var(Expr* node);
static void SS_process_one_cte(PlannerInfo* root, CommonTableExpr* cte, Query* subquery);
static Node*transform_equal_expr(PlannerInfo *root, Query *subQuery,
List *pullUpEqualExpr, Node **quals, bool isLimit, bool isnull = false);
static bool all_replicate_table(Query *query);
static Node* convert_expr_subink_with_agg_targetlist(PlannerInfo *root,
Node **jtlink1,
Node *inout_quals,
SubLink *sublink,
Relids *available_rels,
Node *all_quals,
const char *refname);
static Node* convert_expr_sublink_with_limit_clause(PlannerInfo *root,
Node ** currJoinLink,
SubLink *sublink,
Node *exprQual,
Relids *available_rels,
Node *all_quals, const char *refname);
static bool CanExprHashable(List *pullUpEqualExpr);
static bool safe_pullup_uncorrelated_sublink_where(Node* inout_quals, Query* subQuery, Relids* available_rels);
static bool contain_dml_walker(Node *node, void *context);
static bool recursive_reference_recursive_walker(Node* node);
static bool contain_outer_selfref_walker(Node *node, Index *depth);
static List* make_wintarget_with_aggref(Aggref* aggref, WinmagicContext* wminfo);
static void winmagic_build_targetlist(PlannerInfo* root,
Node* sublink_qual,
WinmagicContext* wminfo);
static Node* winmagic_get_sublink_qual(PlannerInfo* root,
SubLink* sublink,
Node* sublink_expr,
Node* sublink_qual,
TargetEntry* winreftle);
static void winmagic_replace_varlist_varno(Query* dest_qry,
Query* src_qry,
WinmagicContext* wminfo);
static bool quals_are_contained(Query* subquery, Query* query);
static List* generate_quals_list(Node* quals);
static bool parent_contains(Query *query,
Oid left_rel,
AttrNumber left_attno,
Oid right_rel,
AttrNumber right_attno);
static bool parent_contains(Query *query,
Oid left_rel,
AttrNumber left_attno,
Const *op_const);
#define PLANNAMELEN 64
static char *denominate_sublink_name(int sublink_counter)
{
int nRet = 0;
char subname[SUBLINK_COUNTER];
nRet = sprintf_s(subname, sizeof(subname), "sublink_%d", sublink_counter);
securec_check_ss_c(nRet, "\0", "\0");
int newlen = strlen(subname) + 1;
char *subquery_name = (char *)palloc0(newlen);
nRet = strncpy_s(subquery_name, newlen, subname, strlen(subname));
securec_check_ss_c(nRet, "\0", "\0");
return subquery_name;
}
static bool
all_replicate_table(Query *query)
{
Relids varnos = get_relids_in_jointree((Node *) query->jointree, false);
int attnum = 0;
while ((attnum = bms_first_member(varnos)) >= 0) {
RangeTblEntry *r_table = (RangeTblEntry*)rt_fetch(attnum, query->rtable);
if (r_table->rtekind == RTE_RELATION) {
if (GetLocatorType(r_table->relid) == LOCATOR_TYPE_REPLICATED)
continue;
}
return false;
}
return true;
}
/*
* Select a PARAM_EXEC number to identify the given Var as a parameter for
* the current subquery, or for a nestloop's inner scan.
* If the Var already has a param in the current context, return that one.
*/
static int assign_param_for_var(PlannerInfo* root, Var* var)
{
ListCell* ppl = NULL;
PlannerParamItem* pitem = NULL;
Index levelsup;
/* Find the query level the Var belongs to */
for (levelsup = var->varlevelsup; levelsup > 0; levelsup--)
root = root->parent_root;
/* If there's already a matching PlannerParamItem there, just use it */
foreach (ppl, root->plan_params) {
pitem = (PlannerParamItem*)lfirst(ppl);
if (IsA(pitem->item, Var)) {
Var* pvar = (Var*)pitem->item;
/*
* This comparison must match _equalVar(), except for ignoring
* varlevelsup. Note that _equalVar() ignores the location.
*/
if (pvar->varno == var->varno && pvar->varattno == var->varattno && pvar->vartype == var->vartype &&
pvar->vartypmod == var->vartypmod && pvar->varcollid == var->varcollid &&
pvar->varnoold == var->varnoold && pvar->varoattno == var->varoattno)
return pitem->paramId;
}
}
/* Nope, so make a new one */
var = (Var*)copyObject(var);
var->varlevelsup = 0;
pitem = makeNode(PlannerParamItem);
pitem->item = (Node*)var;
pitem->paramId = root->glob->nParamExec++;
root->plan_params = lappend(root->plan_params, pitem);
return pitem->paramId;
}
static Param* initParam(Var* var, int i)
{
Param* retval = makeNode(Param);
retval->paramkind = PARAM_EXEC;
retval->paramid = i;
retval->paramtype = var->vartype;
retval->paramtypmod = var->vartypmod;
retval->paramcollid = var->varcollid;
retval->location = var->location;
return retval;
}
/*
* Generate a Param node to replace the given Var,
* which is expected to have varlevelsup > 0 (ie, it is not local).
*/
static Param* replace_outer_var(PlannerInfo* root, Var* var)
{
int i;
AssertEreport(var->varlevelsup > 0 && var->varlevelsup < root->query_level,
MOD_OPT_SUBPLAN,
"Replaced var should be within valid range");
/* Find the Var in the appropriate plan_params, or add it if not present */
i = assign_param_for_var(root, var);
return initParam(var, i);
}
/*
* Generate a Param node to replace the given Var, which will be supplied
* from an upper NestLoop join node.
*
* This is effectively the same as replace_outer_var, except that we expect
* the Var to be local to the current query level.
*/
Param* assign_nestloop_param_var(PlannerInfo* root, Var* var)
{
int i;
AssertEreport(var->varlevelsup == 0, MOD_OPT_SUBPLAN, "Replaced var should be at current level");
i = assign_param_for_var(root, var);
return initParam(var, i);
}
/*
* @@GaussDB@@
* Target : data partition
* Brief : get PartIterator ParamId from PlannerInfo
* Description :
* Input :
* Output :
* Notes :
*/
int assignPartIteratorParam(PlannerInfo* root)
{
PlannerParamItem* pitem = NULL;
Node* itrParam = NULL; /* just for specifying value to PlannerParamItem.item, represent nothing. */
itrParam = (Node*)palloc(sizeof(Node));
pitem = makeNode(PlannerParamItem);
pitem->item = (Node*)itrParam;
pitem->paramId = SS_assign_special_param(root);
root->plan_params = lappend(root->plan_params, pitem);
return pitem->paramId;
}
/*
* Select a PARAM_EXEC number to identify the given PlaceHolderVar as a
* parameter for the current subquery, or for a nestloop's inner scan.
* If the PHV already has a param in the current context, return that one.
*
* This is just like assign_param_for_var, except for PlaceHolderVars.
*/
static int assign_param_for_placeholdervar(PlannerInfo* root, PlaceHolderVar* phv)
{
ListCell* ppl = NULL;
PlannerParamItem* pitem = NULL;
Index levelsup;
/* Find the query level the PHV belongs to */
for (levelsup = phv->phlevelsup; levelsup > 0; levelsup--)
root = root->parent_root;
/* If there's already a matching PlannerParamItem there, just use it */
foreach (ppl, root->plan_params) {
pitem = (PlannerParamItem*)lfirst(ppl);
if (IsA(pitem->item, PlaceHolderVar)) {
PlaceHolderVar* pphv = (PlaceHolderVar*)pitem->item;
/* We assume comparing the PHIDs is sufficient */
if (pphv->phid == phv->phid)
return pitem->paramId;
}
}
/* Nope, so make a new one */
phv = (PlaceHolderVar*)copyObject(phv);
if (phv->phlevelsup != 0) {
IncrementVarSublevelsUp((Node*)phv, -((int)phv->phlevelsup), 0);
AssertEreport(phv->phlevelsup == 0, MOD_OPT_SUBPLAN, "Placeholder var should be at current level");
}
pitem = makeNode(PlannerParamItem);
pitem->item = (Node*)phv;
pitem->paramId = root->glob->nParamExec++;
root->plan_params = lappend(root->plan_params, pitem);
return pitem->paramId;
}
static Param* getParamPHV(PlaceHolderVar* phv, int i)
{
Param* retval = makeNode(Param);
retval->paramkind = PARAM_EXEC;
retval->paramid = i;
retval->paramtype = exprType((Node*)phv->phexpr);
retval->paramtypmod = exprTypmod((Node*)phv->phexpr);
retval->paramcollid = exprCollation((Node*)phv->phexpr);
retval->location = -1;
return retval;
}
/*
* Generate a Param node to replace the given PlaceHolderVar,
* which is expected to have phlevelsup > 0 (ie, it is not local).
*
* This is just like replace_outer_var, except for PlaceHolderVars.
*/
static Param* replace_outer_placeholdervar(PlannerInfo* root, PlaceHolderVar* phv)
{
int i;
AssertEreport(phv->phlevelsup > 0 && phv->phlevelsup < root->query_level,
MOD_OPT_SUBPLAN,
"Placeholder var should be within valid range");
/* Find the PHV in the appropriate plan_params, or add it if not present */
i = assign_param_for_placeholdervar(root, phv);
return getParamPHV(phv, i);
}
/*
* Generate a Param node to replace the given PlaceHolderVar, which will be
* supplied from an upper NestLoop join node.
*
* This is just like assign_nestloop_param_var, except for PlaceHolderVars.
*/
Param* assign_nestloop_param_placeholdervar(PlannerInfo* root, PlaceHolderVar* phv)
{
int i;
AssertEreport(phv->phlevelsup == 0, MOD_OPT_SUBPLAN, "Placeholder var should be at current level");
i = assign_param_for_placeholdervar(root, phv);
return getParamPHV(phv, i);
}
/*
* Generate a Param node to replace the given Aggref
* which is expected to have agglevelsup > 0 (ie, it is not local).
*/
static Param* replace_outer_agg(PlannerInfo* root, Aggref* agg)
{
Param* retval = NULL;
PlannerParamItem* pitem = NULL;
Index levelsup;
AssertEreport(agg->agglevelsup > 0 && agg->agglevelsup < root->query_level,
MOD_OPT_SUBPLAN,
"Agg expr should be within valid range");
/* Find the query level the Aggref belongs to */
for (levelsup = agg->agglevelsup; levelsup > 0; levelsup--)
root = root->parent_root;
/*
* It does not seem worthwhile to try to match duplicate outer aggs. Just
* make a new slot every time.
*/
agg = (Aggref*)copyObject(agg);
IncrementVarSublevelsUp((Node*)agg, -((int)agg->agglevelsup), 0);
AssertEreport(agg->agglevelsup == 0, MOD_OPT_SUBPLAN, "Agg expr should be at current level");
pitem = makeNode(PlannerParamItem);
pitem->item = (Node*)agg;
pitem->paramId = root->glob->nParamExec++;
root->plan_params = lappend(root->plan_params, pitem);
retval = makeNode(Param);
retval->paramkind = PARAM_EXEC;
retval->paramid = pitem->paramId;
retval->paramtype = agg->aggtype;
retval->paramtypmod = -1;
retval->paramcollid = agg->aggcollid;
retval->location = agg->location;
return retval;
}
/*
* Generate a Param node to replace the given GroupingFunc expression which is
* expected to have agglevelsup > 0 (ie, it is not local).
*/
static Param* replace_outer_grouping(PlannerInfo* root, GroupingFunc* grp)
{
Param* retval = NULL;
PlannerParamItem* pitem = NULL;
Index levelsup;
AssertEreport(grp->agglevelsup > 0 && grp->agglevelsup < root->query_level,
MOD_OPT_SUBPLAN,
"Grouping expr should be within valid range");
/* Find the query level the GroupingFunc belongs to */
for (levelsup = grp->agglevelsup; levelsup > 0; levelsup--)
root = root->parent_root;
/*
* It does not seem worthwhile to try to match duplicate outer aggs. Just
* make a new slot every time.
*/
grp = (GroupingFunc*)copyObject(grp);
IncrementVarSublevelsUp((Node*)grp, -((int)grp->agglevelsup), 0);
AssertEreport(grp->agglevelsup == 0, MOD_OPT_SUBPLAN, "Grouping expr should be at current level");
pitem = makeNode(PlannerParamItem);
pitem->item = (Node*)grp;
pitem->paramId = root->glob->nParamExec++;
root->plan_params = lappend(root->plan_params, pitem);
retval = makeNode(Param);
retval->paramkind = PARAM_EXEC;
retval->paramid = pitem->paramId;
retval->paramtype = exprType((Node*)grp);
retval->paramtypmod = -1;
retval->paramcollid = InvalidOid;
retval->location = grp->location;
return retval;
}
/*
* Generate a new Param node that will not conflict with any other.
*
* This is used to create Params representing subplan outputs.
* We don't need to build a PlannerParamItem for such a Param, but we do
* need to record the PARAM_EXEC slot number as being allocated.
*/
static Param* generate_new_param(PlannerInfo* root, Oid paramtype, int32 paramtypmod, Oid paramcollation)
{
Param* retval = NULL;
retval = makeNode(Param);
retval->paramkind = PARAM_EXEC;
retval->paramid = root->glob->nParamExec++;
retval->paramtype = paramtype;
retval->paramtypmod = paramtypmod;
retval->paramcollid = paramcollation;
retval->location = -1;
return retval;
}
/*
* Assign a (nonnegative) PARAM_EXEC ID for a special parameter (one that
* is not actually used to carry a value at runtime). Such parameters are
* used for special runtime signaling purposes, such as connecting a
* recursive union node to its worktable scan node or forcing plan
* re-evaluation within the EvalPlanQual mechanism. No actual Param node
* exists with this ID, however.
*/
int SS_assign_special_param(PlannerInfo* root)
{
return root->glob->nParamExec++;
}
/*
* Get the datatype/typmod/collation of the first column of the plan's output.
*
* This information is stored for ARRAY_SUBLINK execution and for
* exprType()/exprTypmod()/exprCollation(), which have no way to get at the
* plan associated with a SubPlan node. We really only need the info for
* EXPR_SUBLINK and ARRAY_SUBLINK subplans, but for consistency we save it
* always.
*/
static void get_first_col_type(Plan* plan, Oid* coltype, int32* coltypmod, Oid* colcollation)
{
/* In cases such as EXISTS, tlist might be empty; arbitrarily use VOID */
if (plan->targetlist) {
TargetEntry* tent = (TargetEntry*)linitial(plan->targetlist);
AssertEreport(IsA(tent, TargetEntry), MOD_OPT_SUBPLAN, "Element of targetlist should be TargetEntry");
if (!tent->resjunk) {
*coltype = exprType((Node*)tent->expr);
*coltypmod = exprTypmod((Node*)tent->expr);
*colcollation = exprCollation((Node*)tent->expr);
return;
}
}
*coltype = VOIDOID;
*coltypmod = -1;
*colcollation = InvalidOid;
}
/*
* Description: subquery is initplan or subplan.
* Parameters:
* @in plan_params: param list.
* @in subLinkType: sublink type.
* Return: true if subquery is initplan.
*/
static bool IsInitPlan(List* plan_params, SubLinkType subLinkType)
{
if (plan_params != NIL) {
return false;
}
if (subLinkType == EXISTS_SUBLINK || subLinkType == EXPR_SUBLINK || subLinkType == ARRAY_SUBLINK ||
subLinkType == ROWCOMPARE_SUBLINK) {
return true;
}
return false;
}
/*
* Convert a SubLink (as created by the parser) into a SubPlan.
*
* We are given the SubLink's contained query, type, and testexpr. We are
* also told if this expression appears at top level of a WHERE/HAVING qual.
*
* Note: we assume that the testexpr has been AND/OR flattened (actually,
* it's been through eval_const_expressions), but not converted to
* implicit-AND form; and any SubLinks in it should already have been
* converted to SubPlans. The subquery is as yet untouched, however.
*
* The result is whatever we need to substitute in place of the SubLink
* node in the executable expression. This will be either the SubPlan
* node (if we have to do the subplan as a subplan), or a Param node
* representing the result of an InitPlan, or a row comparison expression
* tree containing InitPlan Param nodes.
*/
static Node* make_subplan(
PlannerInfo* root, Query* orig_subquery, SubLinkType subLinkType, Node* testexpr, bool isTopQual)
{
Query* subquery = NULL;
bool simple_exists = false;
double tuple_fraction;
Plan* plan = NULL;
PlannerInfo* subroot = NULL;
List* plan_params = NIL;
Node* result = NULL;
bool tmp_need_autoanalyze = false;
/*
* Copy the source Query node. This is a quick and dirty kluge to resolve
* the fact that the parser can generate trees with multiple links to the
* same sub-Query node, but the planner wants to scribble on the Query.
* Try to clean this up when we do querytree redesign...
*/
subquery = (Query*)copyObject(orig_subquery);
/*
* If it's an EXISTS subplan, we might be able to simplify it.
*/
if (subLinkType == EXISTS_SUBLINK)
simple_exists = simplify_EXISTS_query(root, subquery);
/*
* For an EXISTS subplan, tell lower-level planner to expect that only the
* first tuple will be retrieved. For ALL and ANY subplans, we will be
* able to stop evaluating if the test condition fails or matches, so very
* often not all the tuples will be retrieved; for lack of a better idea,
* specify 50% retrieval. For EXPR and ROWCOMPARE subplans, use default
* behavior (we're only expecting one row out, anyway).
*
* NOTE: if you change these numbers, also change cost_subplan() in
* path/costsize.c.
*
* XXX If an ANY subplan is uncorrelated, build_subplan may decide to hash
* its output. In that case it would've been better to specify full
* retrieval. At present, however, we can only check hashability after
* we've made the subplan :-(. (Determining whether it'll fit in work_mem
* is the really hard part.) Therefore, we don't want to be too
* optimistic about the percentage of tuples retrieved, for fear of
* selecting a plan that's bad for the materialization case.
*/
if (subLinkType == EXISTS_SUBLINK)
tuple_fraction = 1.0; /* just like a LIMIT 1 */
else if (subLinkType == ALL_SUBLINK || subLinkType == ANY_SUBLINK)
tuple_fraction = 0.5; /* 50% */
else
tuple_fraction = 0.0; /* default behavior */
/* plan_params should not be in use in current query level */
AssertEreport(root->plan_params == NIL, MOD_OPT_SUBPLAN, "Plan_params should not be in use in current query level");
/*
* Generate the plan for the subquery.
*/
/* Set u_sess->opt_cxt.query_dop to forbidden the parallel of subquery. */
int outerDop = u_sess->opt_cxt.query_dop;
if (isIntergratedMachine == false) {
u_sess->opt_cxt.query_dop = 1;
} else {
bool isInitPlan = IsInitPlan(root->plan_params, subLinkType);
if (isInitPlan == false) {
u_sess->opt_cxt.query_dop = 1;
}
}
int dopTmp = u_sess->opt_cxt.query_dop;
/* reset u_sess->analyze_cxt.need_autoanalyze */
tmp_need_autoanalyze = u_sess->analyze_cxt.need_autoanalyze;
u_sess->analyze_cxt.need_autoanalyze = false;
plan = subquery_planner(root->glob, subquery, root, false, tuple_fraction, &subroot, (SUBQUERY_SUBLINK | SUBQUERY_NORMAL));
u_sess->analyze_cxt.need_autoanalyze = tmp_need_autoanalyze;
/* Reset u_sess->opt_cxt.query_dop. */
u_sess->opt_cxt.query_dop = outerDop;
/* Isolate the params needed by this specific subplan */
plan_params = root->plan_params;
root->plan_params = NIL;
/* And convert to SubPlan or InitPlan format. */
result = build_subplan(root, plan, subroot, plan_params, subLinkType, testexpr, true, isTopQual);
#ifdef PGXC
/* This is not necessary for a PGXC Coordinator, we just need one plan */
if (IS_PGXC_COORDINATOR && !IsConnFromCoord())
return result;
#endif
/*
* If it's a correlated EXISTS with an unimportant targetlist, we might be
* able to transform it to the equivalent of an IN and then implement it
* by hashing. We don't have enough information yet to tell which way is
* likely to be better (it depends on the expected number of executions of
* the EXISTS qual, and we are much too early in planning the outer query
* to be able to guess that). So we generate both plans, if possible, and
* leave it to the executor to decide which to use.
*/
if (simple_exists && IsA(result, SubPlan)) {
Node* newtestexpr = NULL;
List* paramIds = NIL;
/* Make a second copy of the original subquery */
subquery = (Query*)copyObject(orig_subquery);
/* and re-simplify */
simple_exists = simplify_EXISTS_query(root, subquery);
if (!simple_exists)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg("Build subPlan failed.. "))));
/* See if it can be converted to an ANY query */
subquery = convert_EXISTS_to_ANY(root, subquery, &newtestexpr, &paramIds);
if (subquery != NULL) {
u_sess->opt_cxt.query_dop = dopTmp;
/* Generate the plan for the ANY subquery; we'll need all rows */
plan = subquery_planner(root->glob, subquery, root, false, 0.0, &subroot, (SUBQUERY_SUBLINK | SUBQUERY_NORMAL));
u_sess->opt_cxt.query_dop = outerDop;
/* Isolate the params needed by this specific subplan */
plan_params = root->plan_params;
root->plan_params = NIL;
/* Now we can check if it'll fit in work_mem */
if (plan != NULL && subplan_is_hashable(plan)) {
SubPlan* hashplan = NULL;
AlternativeSubPlan* asplan = NULL;
/* OK, convert to SubPlan format. */
hashplan =
(SubPlan*)build_subplan(root, plan, subroot, plan_params, ANY_SUBLINK, newtestexpr, false, true);
if (NULL == hashplan)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
(errmsg("convert to SubPlan failed. "))));
/* Check we got what we expected */
AssertEreport(IsA(hashplan, SubPlan), MOD_OPT_SUBPLAN, "Subplan must be hashplan");
AssertEreport(hashplan->parParam == NIL, MOD_OPT_SUBPLAN, "Param of hashplan should be null");
AssertEreport(hashplan->useHashTable, MOD_OPT_SUBPLAN, "Hashtable of hashplan should be used");
/* build_subplan won't have filled in paramIds */
hashplan->paramIds = paramIds;
/* Leave it to the executor to decide which plan to use */
asplan = makeNode(AlternativeSubPlan);
asplan->subplans = list_make2(result, hashplan);
result = (Node*)asplan;
}
}
}
return result;
}
/*
* Build a SubPlan node given the raw inputs --- subroutine for make_subplan
*
* Returns either the SubPlan, or an expression using initplan output Params,
* as explained in the comments for make_subplan.
*/
static Node* build_subplan(PlannerInfo* root, Plan* plan, PlannerInfo* subroot, List* plan_params,
SubLinkType subLinkType, Node* testexpr, bool adjust_testexpr, bool unknownEqFalse)
{
#define MAX_PLAN_NAME_LEN 32
#define MAX_PARAM_LEN 12
Node* result = NULL;
SubPlan* splan = NULL;
bool isInitPlan = false;
ListCell* lc = NULL;
errno_t errorno = EOK;
/*
* Initialize the SubPlan node. Note plan_id, plan_name, and cost fields
* are set further down.
*/
splan = makeNode(SubPlan);
splan->subLinkType = subLinkType;
splan->testexpr = NULL;
splan->paramIds = NIL;
get_first_col_type(plan, &splan->firstColType, &splan->firstColTypmod, &splan->firstColCollation);
splan->useHashTable = false;
splan->unknownEqFalse = unknownEqFalse;
splan->setParam = NIL;
splan->parParam = NIL;
splan->args = NIL;
/*
* Make parParam and args lists of param IDs and expressions that current
* query level will pass to this child plan.
*/
foreach (lc, plan_params) {
PlannerParamItem* pitem = (PlannerParamItem*)lfirst(lc);
Node* arg = pitem->item;
/*
* The Var, PlaceHolderVar, or Aggref has already been adjusted to
* have the correct varlevelsup, phlevelsup, or agglevelsup.
*
* If it's a PlaceHolderVar or Aggref, its arguments might contain
* SubLinks, which have not yet been processed (see the comments for
* SS_replace_correlation_vars). Do that now.
*/
if (IsA(arg, PlaceHolderVar) || IsA(arg, Aggref))
arg = SS_process_sublinks(root, arg, false);
splan->parParam = lappend_int(splan->parParam, pitem->paramId);
splan->args = lappend(splan->args, arg);
}
/*
* Un-correlated or undirect correlated plans of EXISTS, EXPR, ARRAY, or
* ROWCOMPARE types can be used as initPlans. For EXISTS, EXPR, or ARRAY,
* we just produce a Param referring to the result of evaluating the
* initPlan. For ROWCOMPARE, we must modify the testexpr tree to contain
* PARAM_EXEC Params instead of the PARAM_SUBLINK Params emitted by the
* parser.
*/
if (splan->parParam == NIL && subLinkType == EXISTS_SUBLINK) {
Param* prm = NULL;
AssertEreport(testexpr == NULL, MOD_OPT_SUBPLAN, "No testexpr required for exists sublink");
prm = generate_new_param(root, BOOLOID, -1, InvalidOid);
splan->setParam = list_make1_int(prm->paramid);
isInitPlan = true;
result = (Node*)prm;
} else if (splan->parParam == NIL && subLinkType == EXPR_SUBLINK) {
TargetEntry* te = (TargetEntry*)linitial(plan->targetlist);
Param* prm = NULL;
AssertEreport(!te->resjunk, MOD_OPT_SUBPLAN, "Expr sublink shouldn't have junk columns");
AssertEreport(testexpr == NULL, MOD_OPT_SUBPLAN, "No testexpr required for expr sublink");
prm = generate_new_param(
root, exprType((Node*)te->expr), exprTypmod((Node*)te->expr), exprCollation((Node*)te->expr));
splan->setParam = list_make1_int(prm->paramid);
isInitPlan = true;
result = (Node*)prm;
} else if (splan->parParam == NIL && subLinkType == ARRAY_SUBLINK) {
TargetEntry* te = (TargetEntry*)linitial(plan->targetlist);
Oid arraytype;
Param* prm = NULL;
AssertEreport(!te->resjunk, MOD_OPT_SUBPLAN, "Array sublink shouldn't have junk columns");
AssertEreport(testexpr == NULL, MOD_OPT_SUBPLAN, "No testexpr required for array sublink");
arraytype = get_array_type(exprType((Node*)te->expr));
if (!OidIsValid(arraytype))
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_INDETERMINATE_DATATYPE),
errmsg("could not find array type for datatype %s", format_type_be(exprType((Node*)te->expr)))));
prm = generate_new_param(root, arraytype, exprTypmod((Node*)te->expr), exprCollation((Node*)te->expr));
splan->setParam = list_make1_int(prm->paramid);
isInitPlan = true;
result = (Node*)prm;
} else if (splan->parParam == NIL && subLinkType == ROWCOMPARE_SUBLINK) {
/* Adjust the Params */
List* params = NIL;
AssertEreport(testexpr != NULL, MOD_OPT_SUBPLAN, "There should be testexpr required for rowcompare sublink");
params = generate_subquery_params(root, plan->targetlist, &splan->paramIds);
result = convert_testexpr(root, testexpr, params);
splan->setParam = list_copy(splan->paramIds);
isInitPlan = true;
/*
* The executable expression is returned to become part of the outer
* plan's expression tree; it is not kept in the initplan node.
*/
} else {
/*
* Adjust the Params in the testexpr, unless caller said it's not
* needed.
*/
if (testexpr != NULL && adjust_testexpr) {
List* params = NIL;
params = generate_subquery_params(root, plan->targetlist, &splan->paramIds);
splan->testexpr = convert_testexpr(root, testexpr, params);
} else
splan->testexpr = testexpr;
/*
* We can't convert subplans of ALL_SUBLINK or ANY_SUBLINK types to
* initPlans, even when they are uncorrelated or undirect correlated,
* because we need to scan the output of the subplan for each outer
* tuple. But if it's a not-direct-correlated IN (= ANY) test, we
* might be able to use a hashtable to avoid comparing all the tuples.
*/
if (subLinkType == ANY_SUBLINK && splan->parParam == NIL && subplan_is_hashable(plan) &&
testexpr_is_hashable(splan->testexpr))
splan->useHashTable = true;
/*
* Otherwise, we have the option to tack a Material node onto the top
* of the subplan, to reduce the cost of reading it repeatedly. This
* is pointless for a direct-correlated subplan, since we'd have to
* recompute its results each time anyway. For uncorrelated/undirect
* correlated subplans, we add Material unless the subplan's top plan
* node would materialize its output anyway. Also, if enable_material
* is false, then the user does not want us to materialize anything
* unnecessarily, so we don't.
*/
else if (splan->parParam == NIL && u_sess->attr.attr_sql.enable_material &&
!ExecMaterializesOutput(nodeTag(plan)))
plan = materialize_finished_plan(plan, false, root->glob->vectorized);
result = (Node*)splan;
isInitPlan = false;
}
#ifdef ENABLE_MULTIPLE_NODES
/* For init plan, we should make it broadcasted if not */
if (IS_STREAM_PLAN && is_execute_on_datanodes(plan) &&
(isInitPlan || subLinkType == ANY_SUBLINK || subLinkType == ALL_SUBLINK)) {
Plan* lefttree = IsA(plan, Material) ? plan->lefttree : plan;
Distribution* distribution = ng_get_dest_distribution(lefttree);
Distribution* target_distribution = ng_get_correlated_subplan_group_distribution();
if (!is_replicated_plan(plan) && subLinkType == ARRAY_SUBLINK) {
plan = add_broacast_under_local_sort(root, subroot, plan);
}
if (!is_replicated_plan(plan) || (!ng_is_same_group(distribution, target_distribution))) {
plan = make_stream_plan(root, lefttree, NIL, 0.0, target_distribution);
}
/* We need to add materialize for non-init plan to avoid rescan */
if (!isInitPlan && contain_special_plan_node(plan, T_Stream)) {
if (IsA(plan, Material))
((Material*)plan)->materialize_all = true;
else
plan = materialize_finished_plan(plan, true, root->glob->vectorized);
}
}
#endif
/*
* Add the subplan and its PlannerInfo to the global lists.
*/
root->glob->subplans = lappend(root->glob->subplans, plan);
root->glob->subroots = lappend(root->glob->subroots, subroot);
splan->plan_id = list_length(root->glob->subplans);
if (isInitPlan)
root->init_plans = lappend(root->init_plans, splan);
/*
* A parameterless subplan (not initplan) should be prepared to handle
* REWIND efficiently. If it has direct parameters then there's no point
* since it'll be reset on each scan anyway; and if it's an initplan then
* there's no point since it won't get re-run without parameter changes
* anyway. The input of a hashed subplan doesn't need REWIND either.
*/
if (splan->parParam == NIL && !isInitPlan && !splan->useHashTable)
root->glob->rewindPlanIDs = bms_add_member(root->glob->rewindPlanIDs, splan->plan_id);
/* Label the subplan for EXPLAIN purposes */
if (isInitPlan) {
ListCell* lc2 = NULL;
int offset;
const int len = MAX_PLAN_NAME_LEN + MAX_PARAM_LEN * list_length(splan->setParam);
splan->plan_name = (char*)palloc(len);
errorno = sprintf_s(splan->plan_name, len, "InitPlan %d (returns ", splan->plan_id);
securec_check_ss(errorno, "", "");
offset = strlen(splan->plan_name);
foreach (lc2, splan->setParam) {
errorno =
sprintf_s(splan->plan_name + offset, len - offset, "$%d%s", lfirst_int(lc2), lnext(lc2) ? "," : "");
securec_check_ss(errorno, "", "");
offset += strlen(splan->plan_name + offset);
}
errorno = sprintf_s(splan->plan_name + offset, len - offset, ")");
securec_check_ss(errorno, "", "");
} else {
splan->plan_name = (char*)palloc(MAX_PLAN_NAME_LEN);
errorno = sprintf_s(splan->plan_name, MAX_PLAN_NAME_LEN, "SubPlan %d", splan->plan_id);
securec_check_ss(errorno, "", "");
}
/* Lastly, fill in the cost estimates for use later */
cost_subplan(root, splan, plan);
return result;
}
/*
* generate_subquery_params: build a list of Params representing the output
* columns of a sublink's sub-select, given the sub-select's targetlist.
*
* We also return an integer list of the paramids of the Params.
*/
static List* generate_subquery_params(PlannerInfo* root, List* tlist, List** paramIds)
{
List* result = NIL;
List* ids = NIL;
ListCell* lc = NULL;
result = ids = NIL;
foreach (lc, tlist) {
TargetEntry* tent = (TargetEntry*)lfirst(lc);
Param* param = NULL;
if (tent->resjunk)
continue;
param = generate_new_param(
root, exprType((Node*)tent->expr), exprTypmod((Node*)tent->expr), exprCollation((Node*)tent->expr));
result = lappend(result, param);
ids = lappend_int(ids, param->paramid);
}
*paramIds = ids;
return result;
}
/*
* generate_subquery_vars: build a list of Vars representing the output
* columns of a sublink's sub-select, given the sub-select's targetlist.
* The Vars have the specified varno (RTE index).
*/
static List* generate_subquery_vars(PlannerInfo* root, List* tlist, Index varno)
{
List* result = NIL;
ListCell* lc = NULL;
result = NIL;
foreach (lc, tlist) {
TargetEntry* tent = (TargetEntry*)lfirst(lc);
Var* var = NULL;
if (tent->resjunk)
continue;
var = makeVarFromTargetEntry(varno, tent);
result = lappend(result, var);
}
return result;
}
/*
* convert_testexpr: convert the testexpr given by the parser into
* actually executable form. This entails replacing PARAM_SUBLINK Params
* with Params or Vars representing the results of the sub-select. The
* nodes to be substituted are passed in as the List result from
* generate_subquery_params or generate_subquery_vars.
*
* The given testexpr has already been recursively processed by
* process_sublinks_mutator. Hence it can no longer contain any
* PARAM_SUBLINK Params for lower SubLink nodes; we can safely assume that
* any we find are for our own level of SubLink.
*/
static Node* convert_testexpr(PlannerInfo* root, Node* testexpr, List* subst_nodes)
{
convert_testexpr_context context;
context.root = root;
context.subst_nodes = subst_nodes;
return convert_testexpr_mutator(testexpr, &context);
}
static Node* convert_testexpr_mutator(Node* node, convert_testexpr_context* context)
{
if (node == NULL)
return NULL;
if (IsA(node, Param)) {
Param* param = (Param*)node;
if (param->paramkind == PARAM_SUBLINK) {
if (param->paramid <= 0 || param->paramid > list_length(context->subst_nodes))
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
errmsg("unexpected PARAM_SUBLINK ID: %d", param->paramid)));
/*
* We copy the list item to avoid having doubly-linked
* substructure in the modified parse tree. This is probably
* unnecessary when it's a Param, but be safe.
*/
return (Node*)copyObject(list_nth(context->subst_nodes, param->paramid - 1));
}
}
if (IsA(node, SubLink)) {
/*
* If we come across a nested SubLink, it is neither necessary nor
* correct to recurse into it: any PARAM_SUBLINKs we might find inside
* belong to the inner SubLink not the outer. So just return it as-is.
*
* This reasoning depends on the assumption that nothing will pull
* subexpressions into or out of the testexpr field of a SubLink, at
* least not without replacing PARAM_SUBLINKs first. If we did want
* to do that we'd need to rethink the parser-output representation
* altogether, since currently PARAM_SUBLINKs are only unique per
* SubLink not globally across the query. The whole point of
* replacing them with Vars or PARAM_EXEC nodes is to make them
* globally unique before they escape from the SubLink's testexpr.
*
* Note: this can't happen when called during SS_process_sublinks,
* because that recursively processes inner SubLinks first. It can
* happen when called from convert_ANY_sublink_to_join, though.
*/
return node;
}
return expression_tree_mutator(node, (Node* (*)(Node*, void*)) convert_testexpr_mutator, (void*)context);
}
/*
* subplan_is_hashable: can we implement an ANY subplan by hashing?
*/
static bool subplan_is_hashable(Plan* plan)
{
double subquery_size;
/*
* The estimated size of the subquery result must fit in work_mem. (Note:
* we use sizeof(HeapTupleHeaderData) here even though the tuples will
* actually be stored as MinimalTuples; this provides some fudge factor
* for hashtable overhead.)
*/
subquery_size = plan->plan_rows * (MAXALIGN(plan->plan_width) + MAXALIGN(sizeof(HeapTupleHeaderData)));
if (subquery_size > u_sess->attr.attr_memory.work_mem * 1024L)
return false;
return true;
}
/*
* testexpr_is_hashable: is an ANY SubLink's test expression hashable?
*/
static bool testexpr_is_hashable(Node* testexpr)
{
/*
* The testexpr must be a single OpExpr, or an AND-clause containing only
* OpExprs.
*
* The combining operators must be hashable and strict. The need for
* hashability is obvious, since we want to use hashing. Without
* strictness, behavior in the presence of nulls is too unpredictable. We
* actually must assume even more than plain strictness: they can't yield
* NULL for non-null inputs, either (see nodeSubplan.c). However, hash
* indexes and hash joins assume that too.
*/
if (testexpr && IsA(testexpr, OpExpr)) {
if (hash_ok_operator((OpExpr*)testexpr))
return true;
} else if (and_clause(testexpr)) {
ListCell* l = NULL;
foreach (l, ((BoolExpr*)testexpr)->args) {
Node* andarg = (Node*)lfirst(l);
if (!IsA(andarg, OpExpr))
return false;
if (!hash_ok_operator((OpExpr*)andarg))
return false;
}
return true;
}
return false;
}
static Node* convert_joinqual_to_antiqual(Node* node, Query* parse)
{
Node* antiqual = NULL;
if (node == NULL)
return NULL;
switch (nodeTag(node)) {
case T_OpExpr:
antiqual = convert_opexpr_to_boolexpr_for_antijoin(node, parse);
break;
case T_BoolExpr: {
/*Not IN, should be and clause.*/
if (and_clause(node)) {
BoolExpr* boolexpr = (BoolExpr*)node;
List* andarglist = NIL;
ListCell* l = NULL;
foreach (l, boolexpr->args) {
Node* andarg = (Node*)lfirst(l);
Node* expr = NULL;
/* The listcell type of args should be OpExpr. */
expr = convert_opexpr_to_boolexpr_for_antijoin(andarg, parse);
if (expr == NULL)
return NULL;
andarglist = lappend(andarglist, expr);
}
antiqual = (Node*)makeBoolExpr(AND_EXPR, andarglist, boolexpr->location);
} else
return NULL;
} break;
case T_ScalarArrayOpExpr:
case T_RowCompareExpr:
default:
antiqual = NULL;
break;
}
return antiqual;
}
static Node* convert_opexpr_to_boolexpr_for_antijoin(Node* node, Query* parse)
{
Node* boolexpr = NULL;
List* antiqual = NIL;
OpExpr* opexpr = NULL;
if (!IsA(node, OpExpr))
return NULL;
else
opexpr = (OpExpr*)node;
antiqual = (List*)list_make1(opexpr);
Node* larg = (Node*)linitial(opexpr->args);
if (IsA(larg, RelabelType))
larg = (Node*)((RelabelType*)larg)->arg;
if (!check_var_nonnullable(parse, larg))
antiqual = lappend(antiqual, makeNullTest(IS_NULL, (Expr*)copyObject(larg)));
Node* rarg = (Node*)lsecond(opexpr->args);
if (IsA(rarg, RelabelType))
rarg = (Node*)((RelabelType*)rarg)->arg;
if (!check_var_nonnullable(parse, rarg))
antiqual = lappend(antiqual, makeNullTest(IS_NULL, (Expr*)copyObject(rarg)));
if (list_length(antiqual) > 1)
boolexpr = (Node*)makeBoolExprTreeNode(OR_EXPR, antiqual);
else
boolexpr = (Node*)opexpr;
return boolexpr;
}
/*
* check_var_nonnullable
* check if the node is nullable
* Parameters:
* @in query: parse tree of current level
* @in node: the expression that need to check nullable
* Return:
* true if the var has not-null constraint, else false
*/
bool check_var_nonnullable(Query* query, Node* node)
{
bool result = false;
RangeTblEntry* rte = NULL;
Var* var = NULL;
bool isFound = false;
if (node == NULL)
return false;
/* Locate real var from type cast expression */
var = locate_base_var((Expr*)node);
if (var == NULL || !IsA(var, Var))
return false;
/* For parameters that passed from outer level, return false */
if (var->varlevelsup > 0)
return false;
/* Get real var from the base relation */
var = (Var*)copyObject(var);
isFound = get_real_rte_varno_attno(query, &var->varno, &var->varattno);
/* If var appears in full join expr, null can be added */
if (isFound) {
pfree_ext(var);
return false;
}
/* If var appears in the inner side of outer join, null can be added */
if (is_join_inner_side((Node*)query->jointree, (Index)var->varno, false, &isFound)) {
pfree_ext(var);
return false;
}
rte = (RangeTblEntry*)list_nth(query->rtable, var->varno - 1);
switch (rte->rtekind) {
case RTE_RELATION: {
HeapTuple tp;
Form_pg_attribute att_tup;
tp = SearchSysCache(ATTNUM, ObjectIdGetDatum(rte->relid), Int16GetDatum(var->varattno), 0, 0);
if (!HeapTupleIsValid(tp)) {
pfree_ext(var);
return false;
}
att_tup = (Form_pg_attribute)GETSTRUCT(tp);
result = att_tup->attnotnull;
if (!result) {
/* If have information not null constraint. */
result = findConstraintByVar(var, rte->relid, NOT_NULL_CONSTRAINT);
}
ReleaseSysCache(tp);
} break;
case RTE_JOIN:
/* shouldn't touch here */
Assert(false);
break;
case RTE_SUBQUERY:
/* we'll quit for grouping sets case, since null will be added */
if (rte->subquery->groupingSets == NIL) {
TargetEntry* te = (TargetEntry*)list_nth(rte->subquery->targetList, var->varattno - 1);
result = check_var_nonnullable(rte->subquery, (Node*)te->expr);
}
break;
case RTE_FUNCTION:
case RTE_VALUES:
case RTE_CTE:
result = false;
break;
default:
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_UNRECOGNIZED_NODE_TYPE),
errmsg("unrecognized RTE kind: %d", (int)rte->rtekind)));
result = false; /* keep compiler quiet */
}
pfree_ext(var);
return result;
}
/*
* Check expression is hashable + strict
*
* We could use op_hashjoinable() and op_strict(), but do it like this to
* avoid a redundant cache lookup.
*/
static bool hash_ok_operator(OpExpr* expr)
{
Oid opid = expr->opno;
/* quick out if not a binary operator */
if (list_length(expr->args) != 2)
return false;
if (opid == ARRAY_EQ_OP) {
/* array_eq is strict, but must check input type to ensure hashable */
/* XXX record_eq will need same treatment when it becomes hashable */
Node* leftarg = (Node*)linitial(expr->args);
return op_hashjoinable(opid, exprType(leftarg));
} else {
/* else must look up the operator properties */
HeapTuple tup;
Form_pg_operator optup;
tup = SearchSysCache1(OPEROID, ObjectIdGetDatum(opid));
if (!HeapTupleIsValid(tup))
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_CACHE_LOOKUP_FAILED),
errmsg("cache lookup failed for operator %u", opid)));
optup = (Form_pg_operator)GETSTRUCT(tup);
if (!optup->oprcanhash || !func_strict(optup->oprcode)) {
ReleaseSysCache(tup);
return false;
}
ReleaseSysCache(tup);
return true;
}
}
static bool recursive_reference_recursive(Query* parse)
{
/* recursive ctes references itself in as the right argument of the first tier */
if (parse->setOperations == NULL || !IsA(parse->setOperations, SetOperationStmt) ||
((SetOperationStmt*)parse->setOperations)->rarg == NULL ||
!IsA(((SetOperationStmt*)parse->setOperations)->rarg, RangeTblRef)) {
return false;
}
RangeTblRef* rtr = (RangeTblRef*)((SetOperationStmt*)parse->setOperations)->rarg;
RangeTblEntry *rte = rt_fetch(rtr->rtindex, parse->rtable);
List* rightArgs = list_make1(rte);
return range_table_walker(rightArgs, (bool (*)())recursive_reference_recursive_walker, NULL, 0);
}
static bool recursive_reference_recursive_walker(Node* node)
{
if (node == NULL) {
return false;
}
if (IsA(node, Query))
{
Query *query = (Query *) node;
if (query->rtable != NIL) {
ListCell* lc = NULL;
foreach(lc, query->rtable) {
RangeTblEntry *rte = (RangeTblEntry*)lfirst(lc);
if (rte->cterecursive && !rte->self_reference) {
return true;
}
}
}
return query_tree_walker(query, (bool (*)())recursive_reference_recursive_walker, NULL, 0);
}
return expression_tree_walker(node, (bool (*)())recursive_reference_recursive_walker, NULL);
}
/*
* contain_dml: is any subquery not a plain SELECT?
*
* We reject SELECT FOR UPDATE/SHARE as well as INSERT etc.
*/
static bool contain_dml(Node* node)
{
return contain_dml_walker(node, NULL);
}
static bool contain_dml_walker(Node *node, void *context)
{
if (node == NULL) {
return false;
}
if (IsA(node, Query))
{
Query *query = (Query *) node;
if (query->commandType != CMD_SELECT || query->rowMarks != NIL)
return true;
return query_tree_walker(query, (bool (*)())contain_dml_walker, context, 0);
}
return expression_tree_walker(node, (bool (*)())contain_dml_walker, context);
}
/*
* contain_outer_selfref: is there an external recursive self-reference?
*/
static bool contain_outer_selfref(Node* node)
{
Index depth = 0;
/*
* We should be starting with a Query, so that depth will be 1 while
* examining its immediate contents.
*/
Assert(IsA(node, Query));
return contain_outer_selfref_walker(node, &depth);
}
static bool contain_outer_selfref_walker(Node *node, Index *depth)
{
if (node == NULL) {
return false;
}
if (IsA(node, RangeTblEntry)) {
RangeTblEntry* rte = (RangeTblEntry*)node;
/*
* Check for a self-reference to a CTE that's above the Query that our
* search started at.
*/
if (rte->rtekind == RTE_CTE && rte->self_reference && rte->ctelevelsup >= *depth)
return true;
return false; /* allow range_table_walker to continue */
}
if (IsA(node, Query)) {
/* Recurse into subquery, tracking nesting depth properly */
Query* query = (Query*)node;
bool result = false;
(*depth)++;
result = query_tree_walker(query, (bool (*)())contain_outer_selfref_walker, (void*)depth, QTW_EXAMINE_RTES);
(*depth)--;
return result;
}
return expression_tree_walker(node, (bool (*)())contain_outer_selfref_walker, (void*)depth);
}
typedef struct UnderGroupingCxt {
char* ctename;
int depth;
bool under_grouping;
Query* subroot;
} UnderGroupingCxt;
static bool under_grouping_func_walker(Node* node, UnderGroupingCxt* cxt)
{
if (node == NULL) {
return false;
}
/* increase query depth along with encountered subquery */
if (IsA(node, Query)) {
Query* query = (Query*)node;
bool result = false;
Query* save_subroot = cxt->subroot;
cxt->subroot = query;
cxt->depth++;
result = query_tree_walker(query, (bool (*)())under_grouping_func_walker, (void*)cxt, 0);
cxt->depth--;
cxt->subroot = save_subroot;
return result;
}
if (IsA(node, GroupingFunc)) {
bool result = false;
bool save_flag = cxt->under_grouping;
cxt->under_grouping = true;
result = expression_tree_walker(node, (bool (*)())under_grouping_func_walker, (void*)cxt);
cxt->under_grouping = save_flag;
return result;
}
if (IsA(node, Var) && cxt->under_grouping) {
Var* var = (Var*)node;
RangeTblEntry* rte = rt_fetch(var->varno, cxt->subroot->rtable);
if ((int)rte->ctelevelsup == cxt->depth && rte->ctename != NULL && strcmp(rte->ctename, cxt->ctename) == 0) {
return true;
}
}
return expression_tree_walker(node, (bool (*)())under_grouping_func_walker, (void*)cxt);
}
/* walk through the parent query tree to see if the CTE is referenced within grouping functions */
static bool under_grouping_func(Query* parse, CommonTableExpr* cte)
{
if (cte->ctename == NULL) {
return false;
}
UnderGroupingCxt cxt = {cte->ctename, -1, false, parse};
return under_grouping_func_walker((Node*)parse, &cxt);
}
static bool cte_inline_common(CommonTableExpr* cte, char** reason, Query* parse)
{
/*
* Consider inlining the CTE (creating RTE_SUBQUERY RTE(s)) instead of
* implementing it as a separately-planned CTE for common cases.
*
* We cannot inline if any of these conditions hold:
*
* 1. The user said not to (the CTEMaterializeAlways option).
*
* 2. The CTE has side-effects; this includes either not being a plain
* SELECT, or containing volatile functions. Inlining might change
* the side-effects, which would be bad.
*
* 3. The CTE is multiply-referenced and contains a self-reference to
* a recursive CTE outside itself. Inlining would result in multiple
* recursive self-references, which we don't support.
*
* 4. Note that recursive CTE cannot be inlined. But how we handle them
* depend upon whether it is stream-recursive plan or other scenario, so
* it is checked externally by cte_inline() and cte_inline_stream().
*
* 5. CTE that contains subqueries cannot be inlined if they appears in
* grouping functions.
*
* Note: we check for volatile functions last, because that's more
* expensive than the other tests needed.
*/
if (cte->ctematerialized == CTEMaterializeAlways) {
*reason = pstrdup("explicitly declared as materialized");
return false;
} else if (((Query*)cte->ctequery)->commandType != CMD_SELECT || contain_dml(cte->ctequery)) {
*reason = pstrdup("not a plain SELECT statement.");
return false;
} else if ((cte->cterefcount > 1 && contain_outer_selfref(cte->ctequery))) {
*reason = pstrdup("contains a self-reference to a recursive CTE outside");
return false;
} else if (contain_volatile_functions(cte->ctequery, true)) {
*reason = pstrdup("contains volatile function");
return false;
} else if (under_grouping_func(parse, cte)) {
contain_subquery_context context = init_contain_subquery_context();
List* subquery_list = contains_subquery((Node*)cte->ctequery, &context);
if (list_length(subquery_list) != 0) {
*reason = pstrdup("contains subquery while in grouping function");
list_free(subquery_list);
}
return false;
}
return true;
}
static bool cte_inline(CommonTableExpr* cte, Query* parse)
{
/*
* cte_inline common is passed if there is no side effect for inlining.
*
* We have an option whether to inline or not. That should
* always be a win if there's just a single reference, but if the CTE
* is multiply-referenced then it's unclear: inlining adds duplicate
* computations, but the ability to absorb restrictions from the outer
* query level could outweigh that. We do not have nearly enough
* information at this point to tell whether that's true, so we let
* the user express a preference. Our default behavior is to inline
* only singly-referenced CTEs, but a CTE marked CTEMaterializeNever
* will be inlined even if multiply referenced.
* Also, if a singly-referenced CTE is referenced by a subquery, it
* will be not be inlined as default behavior. This is because we do
* not know if this subquery can be pulled up. If it cannot be pulled
* up, we may risk nested subplan execution, which can be disastrous.
*/
char* buf = NULL;
bool ret = cte_inline_common(cte, &buf, parse);
if (ret) {
Assert(buf == NULL);
if (cte->ctematerialized == CTEMaterializeDefault) {
if (cte->referenced_by_subquery) {
buf = pstrdup("CTE is not inlined by default if referenced by subquery");
ret = false;
} else if (cte->cterefcount > 1) {
buf = pstrdup("CTE is not inlined by default if referenced more than once");
ret = false;
}
} else if (cte->cterecursive) {
buf = pstrdup("recursive CTE cannot be inlined");
ret = false;
}
}
if (!ret) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("CTE \"%s\"is not inlined. Reason: %s", cte->ctename, buf))));
}
pfree_ext(buf);
return ret;
}
static bool cte_inline_stream(CommonTableExpr* cte, Query* parse)
{
char* buf = NULL;
Assert(IS_STREAM_PLAN);
if (!u_sess->attr.attr_sql.enable_stream_recursive && cte->cterecursive) {
errno_t sprintf_rc = sprintf_s(u_sess->opt_cxt.not_shipping_info->not_shipping_reason,
NOTPLANSHIPPING_LENGTH,
"Unsupported CTE substitution causes SQL unshipped");
securec_check_ss_c(sprintf_rc, "\0", "\0");
mark_stream_unsupport();
}
if (recursive_reference_recursive((Query*)cte->ctequery)) {
errno_t sprintf_rc = sprintf_s(u_sess->opt_cxt.not_shipping_info->not_shipping_reason,
NOTPLANSHIPPING_LENGTH,
"Recursive CTE references recursive CTE \"%s\"",
cte->ctename);
securec_check_ss_c(sprintf_rc, "\0", "\0");
mark_stream_unsupport();
}
/*
* For stream plan, CTEs only support inline execution. Fallback to pgxc
* plan if inline criteria are violated.
*
* In preference of stream plan, we DO NOT obey the rule of thumb if there
* is no explicit expression of (not) materialized.
*/
if (cte->cterecursive) { /* Recursive CTE will be handled */
return false;
#ifndef ENABLE_MULTIPLE_NODES
} else if (cte->ctematerialized == CTEMaterializeDefault && cte->referenced_by_subquery) {
/*
* if a singly-referenced CTE is referenced by a subquery, it will not be
* inline as the default behavior. This is because we do not know if this
* subquery can be pulled up. If it cannot be pulled up, we may risk nested
* subplan execution, which can be disastrous.
*/
errno_t sprintf_rc = sprintf_s(u_sess->opt_cxt.not_shipping_info->not_shipping_reason,
NOTPLANSHIPPING_LENGTH,
"CTE \"%s\" cannot be inlined. Reason: %s",
cte->ctename, "CTE is not inlined by default if referenced by subquery");
securec_check_ss_c(sprintf_rc, "\0", "\0");
mark_stream_unsupport();
#endif
} else if (!cte_inline_common(cte, &buf, parse)) {
errno_t sprintf_rc = sprintf_s(u_sess->opt_cxt.not_shipping_info->not_shipping_reason,
NOTPLANSHIPPING_LENGTH,
"CTE \"%s\" cannot be inlined. Reason: %s",
cte->ctename, buf);
securec_check_ss_c(sprintf_rc, "\0", "\0");
pfree_ext(buf);
mark_stream_unsupport();
}
return true;
}
/*
* SS_process_one_cte: process a cte in query's WITH list
*
* Working hourse for SS_process_ctes()
*/
static void SS_process_one_cte(PlannerInfo* root, CommonTableExpr* cte, Query* subquery)
{
Plan* plan = NULL;
bool tmp_need_autoanalyze = false;
PlannerInfo* subroot = NULL;
SubPlan* splan;
int paramid;
/*
* Generate the plan for the CTE query. Always plan for full
* retrieval --- we don't have enough info to predict otherwise.
*/
/* reset need_autoanalyze */
tmp_need_autoanalyze = u_sess->analyze_cxt.need_autoanalyze;
u_sess->analyze_cxt.need_autoanalyze = false;
plan = subquery_planner(root->glob, subquery, root, cte->cterecursive, 0.0, &subroot);
u_sess->analyze_cxt.need_autoanalyze = tmp_need_autoanalyze;
/*
* Since the current query level doesn't yet contain any RTEs, it
* should not be possible for the CTE to have requested parameters of
* this level.
*/
if (root->plan_params)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
errmsg("unexpected outer reference in CTE query")));
/*
* Make a SubPlan node for it. This is just enough unlike
* build_subplan that we can't share code.
*
* Note plan_id, plan_name, and cost fields are set further down.
*/
splan = makeNode(SubPlan);
splan->subLinkType = CTE_SUBLINK;
splan->testexpr = NULL;
splan->paramIds = NIL;
get_first_col_type(plan, &splan->firstColType, &splan->firstColTypmod, &splan->firstColCollation);
splan->useHashTable = false;
splan->unknownEqFalse = false;
splan->setParam = NIL;
splan->parParam = NIL;
splan->args = NIL;
/*
* The node can't have any inputs (since it's an initplan), so the
* parParam and args lists remain empty. (It could contain references
* to earlier CTEs' output param IDs, but CTE outputs are not
* propagated via the args list.)
*/
/*
* Assign a param ID to represent the CTE's output. No ordinary
* "evaluation" of this param slot ever happens, but we use the param
* ID for setParam/chgParam signaling just as if the CTE plan were
* returning a simple scalar output. (Also, the executor abuses the
* ParamExecData slot for this param ID for communication among
* multiple CteScan nodes that might be scanning this CTE.)
*/
paramid = SS_assign_special_param(root);
splan->setParam = list_make1_int(paramid);
/*
* Add the subplan and its PlannerInfo to the global lists.
*/
if (IsA(plan, RecursiveUnion)) {
((RecursiveUnion*)plan)->is_used = false;
}
root->glob->subplans = lappend(root->glob->subplans, plan);
root->glob->subroots = lappend(root->glob->subroots, subroot);
splan->plan_id = list_length(root->glob->subplans);
root->init_plans = lappend(root->init_plans, splan);
root->cte_plan_ids = lappend_int(root->cte_plan_ids, splan->plan_id);
/* Label the subplan for EXPLAIN purposes */
splan->plan_name = (char*)palloc(4 + strlen(cte->ctename) + 1);
errno_t errorno = EOK;
errorno = sprintf_s(splan->plan_name, 4 + strlen(cte->ctename) + 1, "CTE %s", cte->ctename);
securec_check_ss(errorno, "", "");
/* Set locator_type */
if (plan->exec_nodes != NULL)
cte->locator_type = plan->exec_nodes->baselocatortype;
/* Lastly, fill in the cost estimates for use later */
cost_subplan(root, splan, plan);
}
typedef struct inline_cte_walker_context
{
const char *ctename; /* name and relative level of target CTE */
Index varlevelsup;
int refcount; /* number of remaining references */
Query *ctequery; /* query to substitute */
} inline_cte_walker_context;
static bool inline_cte_walker(Node *node, inline_cte_walker_context *context)
{
if (node == NULL) {
return false;
}
if (IsA(node, Query))
{
Query *query = (Query *) node;
context->varlevelsup++;
/*
* Visit the query's RTE nodes after their contents; otherwise
* query_tree_walker would descend into the newly inlined CTE query,
* which we don't want.
*/
(void) query_tree_walker(query, (bool (*)())inline_cte_walker, context, QTW_EXAMINE_RTES);
context->varlevelsup--;
return false;
}
else if (IsA(node, RangeTblEntry))
{
RangeTblEntry *rte = (RangeTblEntry *) node;
if (rte->rtekind == RTE_CTE &&
strcmp(rte->ctename, context->ctename) == 0 &&
rte->ctelevelsup == context->varlevelsup) {
/*
* Found a reference to replace. Generate a copy of the CTE query
* with appropriate level adjustment for outer references (e.g.,
* to other CTEs).
*/
Query *newquery = (Query*)copyObject(context->ctequery);
/*
* if correlated cte is referenced in different subquery level,
* we should also adjust correlated params in cte parse tree
*/
if (context->varlevelsup > 0)
IncrementVarSublevelsUp((Node *) newquery, context->varlevelsup, 1);
/*
* Convert the RTE_CTE RTE into a RTE_SUBQUERY.
*
* Historically, a FOR UPDATE clause has been treated as extending
* into views and subqueries, but not into CTEs. We preserve this
* distinction by not trying to push rowmarks into the new
* subquery.
*/
rte->rtekind = RTE_SUBQUERY;
rte->subquery = newquery;
rte->security_barrier = false;
/* Zero out CTE-specific fields */
rte->ctename = NULL;
rte->ctelevelsup = 0;
rte->self_reference = false;
/* Count the number of replacements we've done */
context->refcount--;
}
return false;
}
return expression_tree_walker(node, (bool (*)())inline_cte_walker, context);
}
/*
* inline_cte: convert RTE_CTE references to given CTE into RTE_SUBQUERYs
*/
static void inline_cte(PlannerInfo *root, CommonTableExpr *cte)
{
struct inline_cte_walker_context context;
context.ctename = cte->ctename;
/* Start at varlevelsup = -1 because we'll immediately increment it */
context.varlevelsup = -1;
context.refcount = cte->cterefcount;
context.ctequery = castNode(Query, cte->ctequery);
(void) inline_cte_walker((Node*)root->parse, &context);
/* Mark this CTE as inlined */
cte->cterefcount = -1;
}
/*
* SS_process_ctes: process a query's WITH list
*
* We plan each interesting WITH item and convert it to an initplan.
* A side effect is to fill in root->cte_plan_ids with a list that
* parallels root->parse->cteList and provides the subplan ID for
* each CTE's initplan.
*/
void SS_process_ctes(PlannerInfo* root)
{
ListCell* lc = NULL;
AssertEreport(
root->cte_plan_ids == NIL, MOD_OPT_SUBPLAN, "Plan id shouldn't be assigned before CTE plan generation");
foreach (lc, root->parse->cteList) {
CommonTableExpr* cte = (CommonTableExpr*)lfirst(lc);
CmdType cmdType = ((Query*)cte->ctequery)->commandType;
Query* subquery = NULL;
/*
* Ignore SELECT CTEs that are not actually referenced anywhere or already inlined.
*/
if ((cte->cterefcount == 0 && cmdType == CMD_SELECT) || cte->cterefcount == -1) {
/* Make a dummy entry in cte_plan_ids */
root->cte_plan_ids = lappend_int(root->cte_plan_ids, -1);
continue;
}
/*
* Copy the source Query node. Probably not necessary, but let's keep
* this similar to make_subplan.
*/
subquery = (Query*)copyObject(cte->ctequery);
/* plan_params should not be in use in current query level */
AssertEreport(
root->plan_params == NIL, MOD_OPT_SUBPLAN, "Plan_params should not be in use in current query level");
if (STREAM_RECURSIVECTE_SUPPORTED && cte->cterecursive) {
if (cte_inline_stream(cte, root->parse)) {
inline_cte(root, cte);
/* Make a dummy entry in cte_plan_ids */
root->cte_plan_ids = lappend_int(root->cte_plan_ids, -1);
continue;
}
int save_plan_current_seed = u_sess->opt_cxt.plan_current_seed;
/*
* When recursive CTE is referenced more than one times, we are goting to
* generate each CTE sperately for each references, we have to do so as the
* current SQL execution framework is not supporting an execution plan-tree
* in share-scan mode. In order to improve the stream planning of recursive
* CTE when we encounter in this case, we have to setup the subplan tree
* for each of them
*
* Note: Implement share-scan in SQL execution engine to natively support it
*/
int cterefcount = cte->cterefcount;
while (cterefcount > 0) {
/*
* In cause of CTE refered multi-times, we need the CTE plan identically
* created, in order to do this we reset the current_seed and seed factor
* before we generate subplan for recursive-cte.
*
* We have to do so from historical reasons where distribute-key of CTE
* is held by RTE where it is shared by different references(range table)
* a different CteScan plan could messup the join order, distribution key
* selection logics.
*/
if (cte->cterecursive && cte->cterefcount > 1 &&
u_sess->attr.attr_sql.plan_mode_seed != OPTIMIZE_PLAN) {
set_path_seed_factor_zero();
u_sess->opt_cxt.plan_current_seed = save_plan_current_seed;
}
SS_process_one_cte(root, cte, subquery);
/*
* In order to eliminate the QRW impact on subquery, we need get a new
* COPY of cte->ctequery for this case to plan the subquery of CTE from
* scratch
*/
subquery = (Query*)copyObject(cte->ctequery);
cterefcount--;
}
} else {
/* cte which contains dml should always be processed whether referenced or not */
if (cte->cterefcount < 1 && !contain_dml(cte->ctequery)) {
continue;
}
if ((IS_STREAM_PLAN && cte_inline_stream(cte, root->parse)) ||
(!IS_STREAM_PLAN && cte_inline(cte, root->parse))) {
inline_cte(root, cte);
/* Make a dummy entry in cte_plan_ids */
root->cte_plan_ids = lappend_int(root->cte_plan_ids, -1);
continue;
}
SS_process_one_cte(root, cte, subquery);
}
}
}
static void remove_redundant_distinct_group_by(Query* subselect)
{
if (!ENABLE_REMOVE_REDUNDANT_DISTINCT_GROUP_BY()) {
return;
}
/*
* Remove distinct if distinct-on is not used and there is no limitClause.
*/
if (subselect->distinctClause && !subselect->hasDistinctOn &&
subselect->limitCount == NULL && subselect->limitOffset == NULL) {
list_free_deep(subselect->distinctClause);
subselect->distinctClause = NULL;
}
/*
* Remove GROUP BY if there are no aggregate functions, HAVING clause, grouping
* sets and limitClause.
*/
if (subselect->groupClause && !subselect->hasAggs && !subselect->hasWindowFuncs &&
subselect->havingQual == NULL && subselect->groupingSets == NULL &&
subselect->limitCount == NULL && subselect->limitOffset == NULL) {
list_free_deep(subselect->groupClause);
subselect->groupClause = NULL;
}
}
/*
* convert_ANY_sublink_to_join: try to convert an ANY SubLink to a join
*
* The caller has found an ANY SubLink at the top level of one of the query's
* qual clauses, but has not checked the properties of the SubLink further.
* Decide whether it is appropriate to process this SubLink in join style.
* If so, form a JoinExpr and return it. Return NULL if the SubLink cannot
* be converted to a join.
*
* The only non-obvious input parameter is available_rels: this is the set
* of query rels that can safely be referenced in the sublink expression.
* (We must restrict this to avoid changing the semantics when a sublink
* is present in an outer join's ON qual.) The conversion must fail if
* the converted qual would reference any but these parent-query relids.
*
* On success, the returned JoinExpr has larg = NULL and rarg = the jointree
* item representing the pulled-up subquery. The caller must set larg to
* represent the relation(s) on the lefthand side of the new join, and insert
* the JoinExpr into the upper query's jointree at an appropriate place
* (typically, where the lefthand relation(s) had been). Note that the
* passed-in SubLink must also be removed from its original position in the
* query quals, since the quals of the returned JoinExpr replace it.
* (Notionally, we replace the SubLink with a constant TRUE, then elide the
* redundant constant from the qual.)
*
* On success, the caller is also responsible for recursively applying
* pull_up_sublinks processing to the rarg and quals of the returned JoinExpr.
* (On failure, there is no need to do anything, since pull_up_sublinks will
* be applied when we recursively plan the sub-select.)
*
* Side effects of a successful conversion include adding the SubLink's
* subselect to the query's rangetable, so that it can be referenced in
* the JoinExpr's rarg.
*/
JoinExpr* convert_ANY_sublink_to_join(PlannerInfo* root, SubLink* sublink, bool under_not, Relids available_rels)
{
JoinExpr* result = NULL;
Query* parse = root->parse;
Query* subselect = (Query*)sublink->subselect;
if (has_no_expand_hint(subselect)) {
return NULL;
}
Relids upper_varnos;
int rtindex;
RangeTblEntry* rte = NULL;
RangeTblRef* rtr = NULL;
List* subquery_vars = NIL;
Node* quals = NULL;
AssertEreport(sublink->subLinkType == ANY_SUBLINK, MOD_OPT_REWRITE, "Any sublink is required");
/*
* The sub-select must not refer to any Vars of the parent query. (Vars of
* higher levels should be okay, though.)
*/
if (contain_vars_of_level((Node*)subselect, 1))
return NULL;
/*
* The test expression must contain some Vars of the parent query, else
* it's not gonna be a join. (Note that it won't have Vars referring to
* the subquery, rather Params.)
*/
upper_varnos = pull_varnos(sublink->testexpr);
if (bms_is_empty(upper_varnos))
return NULL;
/*
* However, it can't refer to anything outside available_rels.
*/
if (!bms_is_subset(upper_varnos, available_rels))
return NULL;
/*
* The combining operators and left-hand expressions mustn't be volatile.
*/
if (contain_volatile_functions(sublink->testexpr))
return NULL;
remove_redundant_distinct_group_by(subselect);
/*
* Okay, pull up the sub-select into upper range table.
*
* We rely here on the assumption that the outer query has no references
* to the inner (necessarily true, other than the Vars that we build
* below). Therefore this is a lot easier than what pull_up_subqueries has
* to go through.
*/
rte = addRangeTableEntryForSubquery(NULL, subselect, makeAlias("ANY_subquery", NIL), false, false, true);
parse->rtable = lappend(parse->rtable, rte);
rtindex = list_length(parse->rtable);
/*
* Form a RangeTblRef for the pulled-up sub-select.
*/
rtr = makeNode(RangeTblRef);
rtr->rtindex = rtindex;
/*
* Build a list of Vars representing the subselect outputs.
*/
subquery_vars = generate_subquery_vars(root, subselect->targetList, rtindex);
/*
* Build the new join's qual expression, replacing Params with these Vars.
*/
quals = convert_testexpr(root, sublink->testexpr, subquery_vars);
result = makeNode(JoinExpr);
if (under_not) {
Node* antiquals = NULL;
antiquals = convert_joinqual_to_antiqual(quals, parse);
if (antiquals == NULL)
return NULL;
else
result->quals = antiquals;
result->jointype = JOIN_ANTI;
} else {
result->jointype = JOIN_SEMI;
result->quals = quals;
}
/*
* And finally, build the JoinExpr node.
*/
result->isNatural = false;
result->larg = NULL; /* caller must fill this in */
result->rarg = (Node*)rtr;
result->usingClause = NIL;
result->alias = NULL;
result->rtindex = 0; /* we don't need an RTE for it */
/* Mark query's can_push */
mark_parent_child_pushdown_flag(root->parse, subselect);
return result;
}
/*
* convert_EXISTS_sublink_to_join: try to convert an EXISTS SubLink to a join
*
* The API of this function is identical to convert_ANY_sublink_to_join's,
* except that we also support the case where the caller has found NOT EXISTS,
* so we need an additional input parameter "under_not".
*/
JoinExpr* convert_EXISTS_sublink_to_join(PlannerInfo* root, SubLink* sublink, bool under_not, Relids available_rels)
{
JoinExpr* result = NULL;
Query* parse = root->parse;
Query* subselect = (Query*)sublink->subselect;
if (has_no_expand_hint(subselect)) {
return NULL;
}
Node* whereClause = NULL;
int rtoffset;
int varno;
Relids clause_varnos;
Relids upper_varnos;
AssertEreport(sublink->subLinkType == EXISTS_SUBLINK, MOD_OPT_REWRITE, "Exists sublink is required");
/*
* Can't flatten if it contains WITH. (We could arrange to pull up the
* WITH into the parent query's cteList, but that risks changing the
* semantics, since a WITH ought to be executed once per associated query
* call.) Note that convert_ANY_sublink_to_join doesn't have to reject
* this case, since it just produces a subquery RTE that doesn't have to
* get flattened into the parent query.
*/
if (subselect->cteList)
return NULL;
/*
* Copy the subquery so we can modify it safely (see comments in
* make_subplan).
*/
subselect = (Query*)copyObject(subselect);
/*
* See if the subquery can be simplified based on the knowledge that it's
* being used in EXISTS(). If we aren't able to get rid of its
* targetlist, we have to fail, because the pullup operation leaves us
* with noplace to evaluate the targetlist.
*/
if (!simplify_EXISTS_query(root, subselect))
return NULL;
/*
* Separate out the WHERE clause. (We could theoretically also remove
* top-level plain JOIN/ON clauses, but it's probably not worth the
* trouble.)
*/
whereClause = subselect->jointree->quals;
subselect->jointree->quals = NULL;
/*
* The rest of the sub-select must not refer to any Vars of the parent
* query. (Vars of higher levels should be okay, though.)
*/
if (contain_vars_of_level((Node*)subselect, 1))
return NULL;
/*
* On the other hand, the WHERE clause must contain some Vars of the
* parent query, else it's not gonna be a join.
*/
if (!contain_vars_of_level(whereClause, 1))
return NULL;
/*
* We don't risk optimizing if the WHERE clause is volatile, either.
*/
if (contain_volatile_functions(whereClause))
return NULL;
/*
* The subquery must have a nonempty jointree, but we can make it so.
*/
replace_empty_jointree(subselect);
/*
* Prepare to pull up the sub-select into top range table.
*
* We rely here on the assumption that the outer query has no references
* to the inner (necessarily true). Therefore this is a lot easier than
* what pull_up_subqueries has to go through.
*
* In fact, it's even easier than what convert_ANY_sublink_to_join has to
* do. The machinations of simplify_EXISTS_query ensured that there is
* nothing interesting in the subquery except an rtable and jointree, and
* even the jointree FromExpr no longer has quals. So we can just append
* the rtable to our own and use the FromExpr in our jointree. But first,
* adjust all level-zero varnos in the subquery to account for the rtable
* merger.
*/
rtoffset = list_length(parse->rtable);
OffsetVarNodes((Node*)subselect, rtoffset, 0);
OffsetVarNodes(whereClause, rtoffset, 0);
if (subselect->hintState) {
/* pull up hint */
pull_up_subquery_hint(root, parse, subselect->hintState);
}
/*
* Upper-level vars in subquery will now be one level closer to their
* parent than before; in particular, anything that had been level 1
* becomes level zero.
*/
IncrementVarSublevelsUp((Node*)subselect, -1, 1);
IncrementVarSublevelsUp(whereClause, -1, 1);
/*
* Now that the WHERE clause is adjusted to match the parent query
* environment, we can easily identify all the level-zero rels it uses.
* The ones <= rtoffset belong to the upper query; the ones > rtoffset do
* not.
*/
clause_varnos = pull_varnos(whereClause);
upper_varnos = NULL;
while ((varno = bms_first_member(clause_varnos)) >= 0) {
if (varno <= rtoffset)
upper_varnos = bms_add_member(upper_varnos, varno);
}
bms_free_ext(clause_varnos);
AssertEreport(!bms_is_empty(upper_varnos), MOD_OPT_REWRITE, "Vars from upper query level should be included");
/*
* Now that we've got the set of upper-level varnos, we can make the last
* check: only available_rels can be referenced.
*/
if (!bms_is_subset(upper_varnos, available_rels))
return NULL;
/* Now we can attach the modified subquery rtable to the parent */
parse->rtable = list_concat(parse->rtable, subselect->rtable);
/*
* And finally, build the JoinExpr node.
*/
result = makeNode(JoinExpr);
result->jointype = under_not ? JOIN_ANTI : JOIN_SEMI;
result->isNatural = false;
result->larg = NULL; /* caller must fill this in */
/* flatten out the FromExpr node if it's useless */
if (list_length(subselect->jointree->fromlist) == 1)
result->rarg = (Node*)linitial(subselect->jointree->fromlist);
else
result->rarg = (Node*)subselect->jointree;
result->usingClause = NIL;
result->quals = whereClause;
result->alias = NULL;
result->rtindex = 0; /* we don't need an RTE for it */
/* Mark query's can_push */
mark_parent_child_pushdown_flag(root->parse, subselect);
return result;
}
/*
* simplify_EXISTS_query: remove any useless stuff in an EXISTS's subquery
*
* The only thing that matters about an EXISTS query is whether it returns
* zero or more than zero rows. Therefore, we can remove certain SQL features
* that won't affect that. The only part that is really likely to matter in
* typical usage is simplifying the targetlist: it's a common habit to write
* "SELECT * FROM" even though there is no need to evaluate any columns.
*
* Note: by suppressing the targetlist we could cause an observable behavioral
* change, namely that any errors that might occur in evaluating the tlist
* won't occur, nor will other side-effects of volatile functions. This seems
* unlikely to bother anyone in practice.
*
* Returns TRUE if was able to discard the targetlist, else FALSE.
*/
static bool simplify_EXISTS_query(PlannerInfo *root, Query* query)
{
/*
* We don't try to simplify at all if the query uses set operations,
* aggregates, grouping sets, SRFs, modifying CTEs, HAVING, OFFSET, or FOR
* UPDATE/SHARE; none of these seem likely in normal usage and their
* possible effects are complex. (Note: we could ignore an "OFFSET 0"
* clause, but that traditionally is used as an optimization fence, so we
* don't.)
*/
if (query->commandType != CMD_SELECT || query->setOperations || query->hasAggs || query->groupingSets ||
query->hasWindowFuncs || query->hasModifyingCTE || query->havingQual || query->limitOffset ||
query->rowMarks)
return false;
if (query->is_flt_frame && query->hasTargetSRFs) {
return false;
}
/*
* LIMIT with a constant positive (or NULL) value doesn't affect the
* semantics of EXISTS, so let's ignore such clauses. This is worth doing
* because people accustomed to certain other DBMSes may be in the habit
* of writing EXISTS(SELECT ... LIMIT 1) as an optimization. If there's a
* LIMIT with anything else as argument, though, we can't simplify.
*/
if (query->limitCount) {
/*
* The LIMIT clause has not yet been through eval_const_expressions,
* so we have to apply that here. It might seem like this is a waste
* of cycles, since the only case plausibly worth worrying about is
* "LIMIT 1" ... but what we'll actually see is "LIMIT int8(1::int4)",
* so we have to fold constants or we're not going to recognize it.
*/
Node* node = eval_const_expressions(root, query->limitCount);
Const* limit = NULL;
/* Might as well update the query if we simplified the clause. */
query->limitCount = node;
if (!IsA(node, Const))
return false;
limit = (Const*)node;
Assert(limit->consttype == INT8OID);
if (!limit->constisnull && DatumGetInt64(limit->constvalue) <= 0)
return false;
/* Whether or not the targetlist is safe, we can drop the LIMIT. */
query->limitCount = NULL;
}
/*
* Mustn't throw away the targetlist if it contains set-returning
* functions; those could affect whether zero rows are returned!
*/
if (expression_returns_set((Node*)query->targetList))
return false;
/*
* Otherwise, we can throw away the targetlist, as well as any GROUP,
* WINDOW, DISTINCT, and ORDER BY clauses; none of those clauses will
* change a nonzero-rows result to zero rows or vice versa. (Furthermore,
* since our parsetree representation of these clauses depends on the
* targetlist, we'd better throw them away if we drop the targetlist.)
*/
query->targetList = NIL;
query->groupClause = NIL;
query->windowClause = NIL;
query->distinctClause = NIL;
query->sortClause = NIL;
query->hasDistinctOn = false;
return true;
}
/*
* convert_EXISTS_to_ANY: try to convert EXISTS to a hashable ANY sublink
*
* The subselect is expected to be a fresh copy that we can munge up,
* and to have been successfully passed through simplify_EXISTS_query.
*
* On success, the modified subselect is returned, and we store a suitable
* upper-level test expression at *testexpr, plus a list of the subselect's
* output Params at *paramIds. (The test expression is already Param-ified
* and hence need not go through convert_testexpr, which is why we have to
* deal with the Param IDs specially.)
*
* On failure, returns NULL.
*/
static Query* convert_EXISTS_to_ANY(PlannerInfo* root, Query* subselect, Node** testexpr, List** paramIds)
{
Node* whereClause = NULL;
List* leftargs = NIL;
List* rightargs = NIL;
List* opids = NIL;
List* opcollations = NIL;
List* newWhere = NIL;
List* tlist = NIL;
List* testlist = NIL;
List* paramids = NIL;
ListCell* lc = NULL;
ListCell* rc = NULL;
ListCell* oc = NULL;
ListCell* cc = NULL;
AttrNumber resno;
/*
* Query must not require a targetlist, since we have to insert a new one.
* Caller should have dealt with the case already.
*/
AssertEreport(
subselect->targetList == NIL, MOD_OPT_REWRITE, "Targetlist of rewritten query should already be set to null");
/*
* Separate out the WHERE clause. (We could theoretically also remove
* top-level plain JOIN/ON clauses, but it's probably not worth the
* trouble.)
*/
whereClause = subselect->jointree->quals;
subselect->jointree->quals = NULL;
/*
* The rest of the sub-select must not refer to any Vars of the parent
* query. (Vars of higher levels should be okay, though.)
*
* Note: we need not check for Aggrefs separately because we know the
* sub-select is as yet unoptimized; any uplevel Aggref must therefore
* contain an uplevel Var reference. This is not the case below ...
*/
if (contain_vars_of_level((Node*)subselect, 1))
return NULL;
/*
* We don't risk optimizing if the WHERE clause is volatile, either.
*/
if (contain_volatile_functions(whereClause))
return NULL;
/*
* Clean up the WHERE clause by doing const-simplification etc on it.
* Aside from simplifying the processing we're about to do, this is
* important for being able to pull chunks of the WHERE clause up into the
* parent query. Since we are invoked partway through the parent's
* preprocess_expression() work, earlier steps of preprocess_expression()
* wouldn't get applied to the pulled-up stuff unless we do them here. For
* the parts of the WHERE clause that get put back into the child query,
* this work is partially duplicative, but it shouldn't hurt.
*
* Note: we do not run flatten_join_alias_vars. This is OK because any
* parent aliases were flattened already, and we're not going to pull any
* child Vars (of any description) into the parent.
*
* Note: passing the parent's root to eval_const_expressions is
* technically wrong, but we can get away with it since only the
* boundParams (if any) are used, and those would be the same in a
* subroot.
*/
whereClause = eval_const_expressions(root, whereClause);
whereClause = (Node*)canonicalize_qual((Expr*)whereClause, false);
whereClause = (Node*)make_ands_implicit((Expr*)whereClause);
/*
* We now have a flattened implicit-AND list of clauses, which we try to
* break apart into "outervar = innervar" hash clauses. Anything that
* can't be broken apart just goes back into the newWhere list. Note that
* we aren't trying hard yet to ensure that we have only outer or only
* inner on each side; we'll check that if we get to the end.
*/
leftargs = rightargs = opids = opcollations = newWhere = NIL;
foreach (lc, (List*)whereClause) {
OpExpr* expr = (OpExpr*)lfirst(lc);
if (IsA(expr, OpExpr) && hash_ok_operator(expr)) {
Node* leftarg = (Node*)linitial(expr->args);
Node* rightarg = (Node*)lsecond(expr->args);
if (contain_vars_of_level(leftarg, 1)) {
leftargs = lappend(leftargs, leftarg);
rightargs = lappend(rightargs, rightarg);
opids = lappend_oid(opids, expr->opno);
opcollations = lappend_oid(opcollations, expr->inputcollid);
continue;
}
if (contain_vars_of_level(rightarg, 1)) {
/*
* We must commute the clause to put the outer var on the
* left, because the hashing code in nodeSubplan.c expects
* that. This probably shouldn't ever fail, since hashable
* operators ought to have commutators, but be paranoid.
*/
expr->opno = get_commutator(expr->opno);
if (OidIsValid(expr->opno) && hash_ok_operator(expr)) {
leftargs = lappend(leftargs, rightarg);
rightargs = lappend(rightargs, leftarg);
opids = lappend_oid(opids, expr->opno);
opcollations = lappend_oid(opcollations, expr->inputcollid);
continue;
}
/* If no commutator, no chance to optimize the WHERE clause */
return NULL;
}
}
/* Couldn't handle it as a hash clause */
newWhere = lappend(newWhere, expr);
}
/*
* If we didn't find anything we could convert, fail.
*/
if (leftargs == NIL)
return NULL;
/*
* There mustn't be any parent Vars or Aggs in the stuff that we intend to
* put back into the child query. Note: you might think we don't need to
* check for Aggs separately, because an uplevel Agg must contain an
* uplevel Var in its argument. But it is possible that the uplevel Var
* got optimized away by eval_const_expressions. Consider
*
* SUM(CASE WHEN false THEN uplevelvar ELSE 0 END)
*/
if (contain_vars_of_level((Node*)newWhere, 1) || contain_vars_of_level((Node*)rightargs, 1))
return NULL;
if (root->parse->hasAggs &&
(contain_aggs_of_level((Node*)newWhere, 1) || contain_aggs_of_level((Node*)rightargs, 1)))
return NULL;
/*
* And there can't be any child Vars in the stuff we intend to pull up.
* (Note: we'd need to check for child Aggs too, except we know the child
* has no aggs at all because of simplify_EXISTS_query's check. The same
* goes for window functions.)
*/
if (contain_vars_of_level((Node*)leftargs, 0))
return NULL;
/*
* Also reject sublinks in the stuff we intend to pull up. (It might be
* possible to support this, but doesn't seem worth the complication.)
*/
if (contain_subplans((Node*)leftargs))
return NULL;
/*
* Okay, adjust the sublevelsup in the stuff we're pulling up.
*/
IncrementVarSublevelsUp((Node*)leftargs, -1, 1);
/*
* Put back any child-level-only WHERE clauses.
*/
if (newWhere != NULL)
subselect->jointree->quals = (Node*)make_ands_explicit(newWhere);
/*
* Build a new targetlist for the child that emits the expressions we
* need. Concurrently, build a testexpr for the parent using Params to
* reference the child outputs. (Since we generate Params directly here,
* there will be no need to convert the testexpr in build_subplan.)
*/
tlist = testlist = paramids = NIL;
resno = 1;
/* there's no "forfour" so we have to chase one of the lists manually */
cc = list_head(opcollations);
forthree(lc, leftargs, rc, rightargs, oc, opids)
{
Node* leftarg = (Node*)lfirst(lc);
Node* rightarg = (Node*)lfirst(rc);
Oid opid = lfirst_oid(oc);
Oid opcollation = lfirst_oid(cc);
Param* param = NULL;
cc = lnext(cc);
param = generate_new_param(root, exprType(rightarg), exprTypmod(rightarg), exprCollation(rightarg));
tlist = lappend(tlist, makeTargetEntry((Expr*)rightarg, resno++, NULL, false));
testlist = lappend(
testlist, make_opclause(opid, BOOLOID, false, (Expr*)leftarg, (Expr*)param, InvalidOid, opcollation));
paramids = lappend_int(paramids, param->paramid);
}
/* Put everything where it should go, and we're done */
subselect->targetList = tlist;
*testexpr = (Node*)make_ands_explicit(testlist);
*paramIds = paramids;
return subselect;
}
/*
* Replace correlation vars (uplevel vars) with Params.
*
* Uplevel PlaceHolderVars and aggregates are replaced, too.
*
* Note: it is critical that this runs immediately after SS_process_sublinks.
* Since we do not recurse into the arguments of uplevel PHVs and aggregates,
* they will get copied to the appropriate subplan args list in the parent
* query with uplevel vars not replaced by Params, but only adjusted in level
* (see replace_outer_placeholdervar and replace_outer_agg). That's exactly
* what we want for the vars of the parent level --- but if a PHV's or
* aggregate's argument contains any further-up variables, they have to be
* replaced with Params in their turn. That will happen when the parent level
* runs SS_replace_correlation_vars. Therefore it must do so after expanding
* its sublinks to subplans. And we don't want any steps in between, else
* those steps would never get applied to the argument expressions, either in
* the parent or the child level.
*
* Another fairly tricky thing going on here is the handling of SubLinks in
* the arguments of uplevel PHVs/aggregates. Those are not touched inside the
* intermediate query level, either. Instead, SS_process_sublinks recurses on
* them after copying the PHV or Aggref expression into the parent plan level
* (this is actually taken care of in build_subplan).
*/
Node* SS_replace_correlation_vars(PlannerInfo* root, Node* expr)
{
/* No setup needed for tree walk, so away we go */
return replace_correlation_vars_mutator(expr, root);
}
static Node* replace_correlation_vars_mutator(Node* node, PlannerInfo* root)
{
if (node == NULL)
return NULL;
if (IsA(node, Var)) {
if (((Var*)node)->varlevelsup > 0)
return (Node*)replace_outer_var(root, (Var*)node);
}
if (IsA(node, PlaceHolderVar)) {
if (((PlaceHolderVar*)node)->phlevelsup > 0)
return (Node*)replace_outer_placeholdervar(root, (PlaceHolderVar*)node);
}
if (IsA(node, Aggref)) {
if (((Aggref*)node)->agglevelsup > 0)
return (Node*)replace_outer_agg(root, (Aggref*)node);
}
if (IsA(node, GroupingFunc)) {
if (((GroupingFunc*)node)->agglevelsup > 0)
return (Node*)replace_outer_grouping(root, (GroupingFunc*)node);
}
return expression_tree_mutator(node, (Node* (*)(Node*, void*)) replace_correlation_vars_mutator, (void*)root);
}
/*
* Expand SubLinks to SubPlans in the given expression.
*
* The isQual argument tells whether or not this expression is a WHERE/HAVING
* qualifier expression. If it is, any sublinks appearing at top level need
* not distinguish FALSE from UNKNOWN return values.
*/
Node* SS_process_sublinks(PlannerInfo* root, Node* expr, bool isQual)
{
process_sublinks_context context;
context.root = root;
context.isTopQual = isQual;
return process_sublinks_mutator(expr, &context);
}
static Node* process_sublinks_mutator(Node* node, process_sublinks_context* context)
{
process_sublinks_context locContext;
locContext.root = context->root;
locContext.isTopQual = false;
if (node == NULL)
return NULL;
if (IsA(node, SubLink)) {
SubLink* sublink = (SubLink*)node;
Node* testexpr = NULL;
/*
* First, recursively process the lefthand-side expressions, if any.
* They're not top-level anymore.
*/
locContext.isTopQual = false;
testexpr = process_sublinks_mutator(sublink->testexpr, &locContext);
/*
* Now build the SubPlan node and make the expr to return.
*/
return make_subplan(
context->root, (Query*)sublink->subselect, sublink->subLinkType, testexpr, context->isTopQual);
}
/*
* Don't recurse into the arguments of an outer PHV or aggregate here. Any
* SubLinks in the arguments have to be dealt with at the outer query
* level; they'll be handled when build_subplan collects the PHV or Aggref
* into the arguments to be passed down to the current subplan.
*/
if (IsA(node, PlaceHolderVar)) {
if (((PlaceHolderVar*)node)->phlevelsup > 0)
return node;
} else if (IsA(node, Aggref)) {
if (((Aggref*)node)->agglevelsup > 0)
return node;
}
/*
* We should never see a SubPlan expression in the input (since this is
* the very routine that creates 'em to begin with). But if this query is
* copied when doing full join rewritting, this is OK.
* We shouldn't find ourselves invoked directly on a Query, either.
*/
if (!context->root->parse->is_from_full_join_rewrite) {
AssertEreport(!IsA(node, SubPlan), MOD_OPT_SUBPLAN, "A subplan expression shouldn't exist in the input");
AssertEreport(
!IsA(node, AlternativeSubPlan), MOD_OPT_SUBPLAN, "AlternativeSubPlan shouldn't exist in the input");
}
AssertEreport(!IsA(node, Query), MOD_OPT_SUBPLAN, "We shouldn't invoke directly on a Query");
/*
* Because make_subplan() could return an AND or OR clause, we have to
* take steps to preserve AND/OR flatness of a qual. We assume the input
* has been AND/OR flattened and so we need no recursion here.
*
* (Due to the coding here, we will not get called on the List subnodes of
* an AND; and the input is *not* yet in implicit-AND format. So no check
* is needed for a bare List.)
*
* Anywhere within the top-level AND/OR clause structure, we can tell
* make_subplan() that NULL and FALSE are interchangeable. So isTopQual
* propagates down in both cases. (Note that this is unlike the meaning
* of "top level qual" used in most other places in Postgres.)
*/
if (and_clause(node)) {
List* newargs = NIL;
ListCell* l = NULL;
/* Still at qual top-level */
locContext.isTopQual = context->isTopQual;
foreach (l, ((BoolExpr*)node)->args) {
Node* newarg = NULL;
newarg = process_sublinks_mutator((Node*)lfirst(l), &locContext);
if (and_clause(newarg))
newargs = list_concat(newargs, ((BoolExpr*)newarg)->args);
else
newargs = lappend(newargs, newarg);
}
return (Node*)make_andclause(newargs);
}
if (or_clause(node)) {
List* newargs = NIL;
ListCell* l = NULL;
/* Still at qual top-level */
locContext.isTopQual = context->isTopQual;
foreach (l, ((BoolExpr*)node)->args) {
Node* newarg = NULL;
newarg = process_sublinks_mutator((Node*)lfirst(l), &locContext);
if (newarg == NULL)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
(errmsg("Fail to process sublinks mutator."))));
if (or_clause(newarg))
newargs = list_concat(newargs, ((BoolExpr*)newarg)->args);
else
newargs = lappend(newargs, newarg);
}
return (Node*)make_orclause(newargs);
}
/*
* If we recurse down through anything other than an AND or OR node, we
* are definitely not at top qual level anymore.
*/
locContext.isTopQual = false;
return expression_tree_mutator(node, (Node* (*)(Node*, void*)) process_sublinks_mutator, (void*)&locContext);
}
/*
* SS_finalize_plan - do final sublink and parameter processing for a
* completed Plan.
*
* This recursively computes the extParam and allParam sets for every Plan
* node in the given plan tree. It also optionally attaches any previously
* generated InitPlans to the top plan node. (Any InitPlans should already
* have been put through SS_finalize_plan.)
*/
void SS_finalize_plan(PlannerInfo* root, Plan* plan, bool attach_initplans)
{
Bitmapset* valid_params = NULL;
Bitmapset* initExtParam = NULL;
Bitmapset* initSetParam = NULL;
Cost initplan_cost;
PlannerInfo* proot = NULL;
ListCell* l = NULL;
/*
* Examine any initPlans to determine the set of external params they
* reference, the set of output params they supply, and their total cost.
* We'll use at least some of this info below. (Note we are assuming that
* finalize_plan doesn't touch the initPlans.)
*
* In the case where attach_initplans is false, we are assuming that the
* existing initPlans are siblings that might supply params needed by the
* current plan.
*/
initExtParam = initSetParam = NULL;
initplan_cost = 0;
foreach (l, root->init_plans) {
SubPlan* initsubplan = (SubPlan*)lfirst(l);
Plan* initplan = planner_subplan_get_plan(root, initsubplan);
ListCell* l2 = NULL;
initExtParam = bms_add_members(initExtParam, initplan->extParam);
foreach (l2, initsubplan->setParam) {
initSetParam = bms_add_member(initSetParam, lfirst_int(l2));
}
initplan_cost += initsubplan->startup_cost + initsubplan->per_call_cost;
}
/*
* Now determine the set of params that are validly referenceable in this
* query level; to wit, those available from outer query levels plus the
* output parameters of any local initPlans. (We do not include output
* parameters of regular subplans. Those should only appear within the
* testexpr of SubPlan nodes, and are taken care of locally within
* finalize_primnode. Likewise, special parameters that are generated by
* nodes such as ModifyTable are handled within finalize_plan.)
*/
valid_params = bms_copy(initSetParam);
for (proot = root->parent_root; proot != NULL; proot = proot->parent_root) {
/* Include ordinary Var/PHV/Aggref params */
foreach (l, proot->plan_params) {
PlannerParamItem* pitem = (PlannerParamItem*)lfirst(l);
valid_params = bms_add_member(valid_params, pitem->paramId);
}
/* Include any outputs of outer-level initPlans */
foreach (l, proot->init_plans) {
SubPlan* initsubplan = (SubPlan*)lfirst(l);
ListCell* l2 = NULL;
foreach (l2, initsubplan->setParam) {
valid_params = bms_add_member(valid_params, lfirst_int(l2));
}
}
/* Include worktable ID, if a recursive query is being planned */
if (proot->wt_param_id >= 0)
valid_params = bms_add_member(valid_params, proot->wt_param_id);
}
/*
* Now recurse through plan tree.
*/
(void)finalize_plan(root, plan, valid_params, NULL);
bms_free_ext(valid_params);
/*
* Finally, attach any initPlans to the topmost plan node, and add their
* extParams to the topmost node's, too. However, any setParams of the
* initPlans should not be present in the topmost node's extParams, only
* in its allParams. (As of PG 8.1, it's possible that some initPlans
* have extParams that are setParams of other initPlans, so we have to
* take care of this situation explicitly.)
*
* We also add the eval cost of each initPlan to the startup cost of the
* top node. This is a conservative overestimate, since in fact each
* initPlan might be executed later than plan startup, or even not at all.
*/
if (attach_initplans) {
plan->initPlan = root->init_plans;
root->init_plans = NIL; /* make sure they're not attached twice */
/* allParam must include all these params */
plan->allParam = bms_add_members(plan->allParam, initExtParam);
plan->allParam = bms_add_members(plan->allParam, initSetParam);
/* extParam must include any child extParam */
plan->extParam = bms_add_members(plan->extParam, initExtParam);
/* but extParam shouldn't include any setParams */
plan->extParam = bms_del_members(plan->extParam, initSetParam);
/* ensure extParam is exactly NULL if it's empty */
if (bms_is_empty(plan->extParam))
plan->extParam = NULL;
plan->startup_cost += initplan_cost;
plan->total_cost += initplan_cost;
}
}
/*
* @Description: finalize_agg_primnode: find all Aggref nodes in the given expression tree,
* and add IDs of all PARAM_EXEC params appearing within their aggregated
* arguments to the result set.
* @in node: Need judge node.
* @out context: Keep paramids struct.
*/
static bool finalize_agg_primnode(Node* node, finalize_primnode_context* context)
{
if (node == NULL) {
return false;
}
if (IsA(node, Aggref)) {
Aggref* agg = (Aggref*)node;
/* we should not consider the direct arguments, if any */
(void)finalize_primnode((Node*)agg->args, context);
(void)finalize_primnode((Node*)agg->aggfilter, context);
return false; /* there can't be any Aggrefs below here */
}
return expression_tree_walker(node, (bool (*)())finalize_agg_primnode, (void*)context);
}
static void finalize_plans(
PlannerInfo* root, finalize_primnode_context* context, List* plans, Bitmapset* valid_params, Bitmapset* scan_params)
{
ListCell* lc = NULL;
foreach (lc, plans) {
context->paramids =
bms_add_members(context->paramids, finalize_plan(root, (Plan*)lfirst(lc), valid_params, scan_params));
}
}
/*
* Recursive processing of all nodes in the plan tree
*
* valid_params is the set of param IDs considered valid to reference in
* this plan node or its children.
* scan_params is a set of param IDs to force scan plan nodes to reference.
* This is for EvalPlanQual support, and is always NULL at the top of the
* recursion.
*
* The return value is the computed allParam set for the given Plan node.
* This is just an internal notational convenience.
*/
static Bitmapset* finalize_plan(PlannerInfo* root, Plan* plan, Bitmapset* valid_params, Bitmapset* scan_params)
{
finalize_primnode_context context;
int locally_added_param;
Bitmapset* nestloop_params = NULL;
Bitmapset* child_params = NULL;
if (plan == NULL)
return NULL;
context.root = root;
context.paramids = NULL; /* initialize set to empty */
locally_added_param = -1; /* there isn't one */
nestloop_params = NULL; /* there aren't any */
/*
* When we call finalize_primnode, context.paramids sets are automatically
* merged together. But when recursing to self, we have to do it the hard
* way. We want the paramids set to include params in subplans as well as
* at this level.
*/
/* Find params in targetlist and qual */
(void)finalize_primnode((Node*)plan->targetlist, &context);
(void)finalize_primnode((Node*)plan->qual, &context);
/* Check additional node-type-specific fields */
switch (nodeTag(plan)) {
case T_BaseResult:
(void)finalize_primnode(((BaseResult*)plan)->resconstantqual, &context);
break;
case T_SeqScan:
case T_CStoreScan:
#ifdef ENABLE_MULTIPLE_NODES
case T_TsStoreScan:
#endif /* ENABLE_MULTIPLE_NODES */
if (((Scan*)plan)->tablesample) {
(void)finalize_primnode((Node*)((Scan*)plan)->tablesample, &context);
}
context.paramids = bms_add_members(context.paramids, scan_params);
break;
case T_IndexScan:
(void)finalize_primnode((Node*)((IndexScan*)plan)->indexqual, &context);
(void)finalize_primnode((Node*)((IndexScan*)plan)->indexorderby, &context);
/*
* we need not look at indexqualorig, since it will have the same
* param references as indexqual. Likewise, we can ignore
* indexorderbyorig.
*/
context.paramids = bms_add_members(context.paramids, scan_params);
break;
case T_IndexOnlyScan:
(void)finalize_primnode((Node*)((IndexOnlyScan*)plan)->indexqual, &context);
(void)finalize_primnode((Node*)((IndexOnlyScan*)plan)->indexorderby, &context);
/*
* we need not look at indextlist, since it cannot contain Params.
*/
context.paramids = bms_add_members(context.paramids, scan_params);
break;
case T_BitmapIndexScan:
(void)finalize_primnode((Node*)((BitmapIndexScan*)plan)->indexqual, &context);
/*
* we need not look at indexqualorig, since it will have the same
* param references as indexqual.
*/
break;
case T_BitmapHeapScan:
(void)finalize_primnode((Node*)((BitmapHeapScan*)plan)->bitmapqualorig, &context);
context.paramids = bms_add_members(context.paramids, scan_params);
break;
case T_CStoreIndexScan:
(void)finalize_primnode((Node*)((CStoreIndexScan*)plan)->indexqual, &context);
(void)finalize_primnode((Node*)((CStoreIndexScan*)plan)->indexorderby, &context);
(void)finalize_primnode((Node*)((CStoreIndexScan*)plan)->cstorequal, &context);
context.paramids = bms_add_members(context.paramids, scan_params);
break;
case T_CStoreIndexCtidScan:
(void)finalize_primnode((Node*)((CStoreIndexCtidScan*)plan)->indexqual, &context);
context.paramids = bms_add_members(context.paramids, scan_params);
break;
case T_CStoreIndexHeapScan:
(void)finalize_primnode((Node*)((CStoreIndexHeapScan*)plan)->bitmapqualorig, &context);
context.paramids = bms_add_members(context.paramids, scan_params);
break;
case T_TidScan:
(void)finalize_primnode((Node*)((TidScan*)plan)->tidquals, &context);
context.paramids = bms_add_members(context.paramids, scan_params);
break;
case T_SubqueryScan:
/*
* In a SubqueryScan, SS_finalize_plan has already been run on the
* subplan by the inner invocation of subquery_planner, so there's
* no need to do it again. Instead, just pull out the subplan's
* extParams list, which represents the params it needs from my
* level and higher levels.
*/
context.paramids = bms_add_members(context.paramids, ((SubqueryScan*)plan)->subplan->extParam);
/* We need scan_params too, though */
context.paramids = bms_add_members(context.paramids, scan_params);
break;
case T_FunctionScan:
(void)finalize_primnode(((FunctionScan*)plan)->funcexpr, &context);
context.paramids = bms_add_members(context.paramids, scan_params);
break;
case T_ValuesScan:
(void)finalize_primnode((Node*)((ValuesScan*)plan)->values_lists, &context);
context.paramids = bms_add_members(context.paramids, scan_params);
break;
case T_CteScan: {
/*
* You might think we should add the node's cteParam to
* paramids, but we shouldn't because that param is just a
* linkage mechanism for multiple CteScan nodes for the same
* CTE; it is never used for changed-param signaling. What we
* have to do instead is to find the referenced CTE plan and
* incorporate its external paramids, so that the correct
* things will happen if the CTE references outer-level
* variables. See test cases for bug #4902.
*/
int plan_id = ((CteScan*)plan)->ctePlanId;
Plan* cteplan = NULL;
/* so, do this ... */
if (plan_id < 1 || plan_id > list_length(root->glob->subplans))
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
errmsg("could not find plan for CteScan referencing plan ID %d", plan_id)));
cteplan = (Plan*)list_nth(root->glob->subplans, plan_id - 1);
context.paramids = bms_add_members(context.paramids, cteplan->extParam);
#ifdef NOT_USED
/* ... but not this */
context.paramids = bms_add_member(context.paramids, ((CteScan*)plan)->cteParam);
#endif
context.paramids = bms_add_members(context.paramids, scan_params);
} break;
case T_WorkTableScan:
context.paramids = bms_add_member(context.paramids, ((WorkTableScan*)plan)->wtParam);
context.paramids = bms_add_members(context.paramids, scan_params);
break;
case T_ForeignScan:
(void)finalize_primnode((Node*)((ForeignScan*)plan)->fdw_exprs, &context);
context.paramids = bms_add_members(context.paramids, scan_params);
break;
case T_ExtensiblePlan: {
ExtensiblePlan* cscan = (ExtensiblePlan*)plan;
(void)finalize_primnode((Node*)cscan->extensible_exprs, &context);
/* We assume extensible_plan_tlist cannot contain Params */
context.paramids = bms_add_members(context.paramids, scan_params);
/* child nodes if any */
finalize_plans(root, &context, cscan->extensible_plans, valid_params, scan_params);
} break;
case T_ModifyTable: {
ModifyTable* mtplan = (ModifyTable*)plan;
/* Force descendant scan nodes to reference epqParam */
locally_added_param = mtplan->epqParam;
valid_params = bms_add_member(bms_copy(valid_params), locally_added_param);
scan_params = bms_add_member(bms_copy(scan_params), locally_added_param);
(void)finalize_primnode((Node*)mtplan->returningLists, &context);
(void)finalize_primnode((Node*)mtplan->updateTlist, &context);
(void)finalize_primnode((Node*)mtplan->upsertWhere, &context);
finalize_plans(root, &context, mtplan->plans, valid_params, scan_params);
} break;
#ifdef PGXC
case T_RemoteQuery:
context.paramids = bms_add_members(context.paramids, scan_params);
break;
#endif
case T_Append: {
finalize_plans(root, &context, ((Append*)plan)->appendplans, valid_params, scan_params);
} break;
case T_MergeAppend: {
finalize_plans(root, &context, ((MergeAppend*)plan)->mergeplans, valid_params, scan_params);
} break;
case T_BitmapAnd: {
finalize_plans(root, &context, ((BitmapAnd*)plan)->bitmapplans, valid_params, scan_params);
} break;
case T_BitmapOr: {
finalize_plans(root, &context, ((BitmapOr*)plan)->bitmapplans, valid_params, scan_params);
} break;
case T_CStoreIndexAnd: {
finalize_plans(root, &context, ((CStoreIndexAnd*)plan)->bitmapplans, valid_params, scan_params);
} break;
case T_CStoreIndexOr: {
finalize_plans(root, &context, ((CStoreIndexOr*)plan)->bitmapplans, valid_params, scan_params);
} break;
case T_NestLoop: {
ListCell* l = NULL;
(void)finalize_primnode((Node*)((Join*)plan)->joinqual, &context);
/* collect set of params that will be passed to right child */
foreach (l, ((NestLoop*)plan)->nestParams) {
NestLoopParam* nlp = (NestLoopParam*)lfirst(l);
nestloop_params = bms_add_member(nestloop_params, nlp->paramno);
}
} break;
case T_MergeJoin:
(void)finalize_primnode((Node*)((Join*)plan)->joinqual, &context);
(void)finalize_primnode((Node*)((MergeJoin*)plan)->mergeclauses, &context);
break;
case T_HashJoin: {
(void)finalize_primnode((Node*)((Join*)plan)->joinqual, &context);
(void)finalize_primnode((Node*)((HashJoin*)plan)->hashclauses, &context);
/*
* If there's already params, then check if there's param in hashkey
* of inner table, then we should rebuild hashtable since hash key
* changes for every rescan
*/
if (!bms_is_empty(context.paramids)) {
ListCell* lc = NULL;
List* inner_hash_clause = NIL;
foreach (lc, ((HashJoin*)plan)->hashclauses) {
OpExpr* hclause = (OpExpr*)lfirst(lc);
AssertEreport(IsA(hclause, OpExpr), MOD_OPT_SUBPLAN, "hashjoin clause should be opExpr");
inner_hash_clause = lappend(inner_hash_clause, lsecond(hclause->args));
}
finalize_primnode_context inner_context;
inner_context.root = root;
inner_context.paramids = NULL; /* initialize set to empty */
(void)finalize_primnode((Node*)inner_hash_clause, &inner_context);
list_free_ext(inner_hash_clause);
if (inner_context.paramids != NULL) {
((HashJoin*)plan)->rebuildHashTable = true;
bms_free_ext(inner_context.paramids);
}
}
} break;
case T_Limit:
(void)finalize_primnode(((Limit*)plan)->limitOffset, &context);
(void)finalize_primnode(((Limit*)plan)->limitCount, &context);
break;
case T_RecursiveUnion:
/* child nodes are allowed to reference wtParam */
locally_added_param = ((RecursiveUnion*)plan)->wtParam;
valid_params = bms_add_member(bms_copy(valid_params), locally_added_param);
/* wtParam does *not* get added to scan_params */
break;
case T_LockRows:
/* Force descendant scan nodes to reference epqParam */
locally_added_param = ((LockRows*)plan)->epqParam;
valid_params = bms_add_member(bms_copy(valid_params), locally_added_param);
scan_params = bms_add_member(bms_copy(scan_params), locally_added_param);
break;
case T_Agg: {
Agg* agg = (Agg*)plan;
/*
* AGG_HASHED plans need to know which Params are referenced
* in aggregate calls. Do a separate scan to identify them.
*/
if (agg->aggstrategy == AGG_HASHED || agg->aggstrategy == AGG_PLAIN) {
finalize_primnode_context aggcontext;
aggcontext.root = root;
aggcontext.paramids = NULL;
finalize_agg_primnode((Node*)agg->plan.targetlist, &aggcontext);
finalize_agg_primnode((Node*)agg->plan.qual, &aggcontext);
agg->aggParams = aggcontext.paramids;
}
} break;
case T_WindowAgg:
(void)finalize_primnode(((WindowAgg*)plan)->startOffset, &context);
(void)finalize_primnode(((WindowAgg*)plan)->endOffset, &context);
break;
case T_ProjectSet:
case T_Hash:
case T_Material:
case T_Sort:
case T_SortGroup:
case T_Unique:
case T_SetOp:
case T_Group:
case T_Stream:
case T_PartIterator:
case T_StartWithOp:
#ifdef USE_SPQ
case T_ShareInputScan:
#endif
break;
default:
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_UNRECOGNIZED_NODE_TYPE),
errmsg("unrecognized node type: %d", (int)nodeTag(plan))));
}
/* Process left and right child plans, if any */
child_params = finalize_plan(root, plan->lefttree, valid_params, scan_params);
context.paramids = bms_add_members(context.paramids, child_params);
if (nestloop_params != NULL) {
/* right child can reference nestloop_params as well as valid_params */
child_params = finalize_plan(root, plan->righttree, bms_union(nestloop_params, valid_params), scan_params);
/* ... and they don't count as parameters used at my level */
child_params = bms_difference(child_params, nestloop_params);
bms_free_ext(nestloop_params);
} else {
/* easy case */
child_params = finalize_plan(root, plan->righttree, valid_params, scan_params);
}
context.paramids = bms_add_members(context.paramids, child_params);
/*
* Any locally generated parameter doesn't count towards its generating
* plan node's external dependencies. (Note: if we changed valid_params
* and/or scan_params, we leak those bitmapsets; not worth the notational
* trouble to clean them up.)
*/
if (locally_added_param >= 0) {
context.paramids = bms_del_member(context.paramids, locally_added_param);
}
/* Now we have all the paramids */
if (!bms_is_subset(context.paramids, valid_params))
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
errmsg("plan should not reference subplan's variable")));
/*
* Note: by definition, extParam and allParam should have the same value
* in any plan node that doesn't have child initPlans. We set them equal
* here, and later SS_finalize_plan will update them properly in node(s)
* that it attaches initPlans to.
*
* For speed at execution time, make sure extParam/allParam are actually
* NULL if they are empty sets.
*/
if (bms_is_empty(context.paramids)) {
plan->extParam = NULL;
plan->allParam = NULL;
} else {
plan->extParam = context.paramids;
plan->allParam = bms_copy(context.paramids);
}
return plan->allParam;
}
/*
* finalize_primnode: add IDs of all PARAM_EXEC params appearing in the given
* expression tree to the result set.
*/
static bool finalize_primnode(Node* node, finalize_primnode_context* context)
{
if (node == NULL)
return false;
if (IsA(node, Param)) {
if (((Param*)node)->paramkind == PARAM_EXEC) {
int paramid = ((Param*)node)->paramid;
context->paramids = bms_add_member(context->paramids, paramid);
}
return false; /* no more to do here */
}
if (IsA(node, SubPlan)) {
SubPlan* subplan = (SubPlan*)node;
Plan* plan = planner_subplan_get_plan(context->root, subplan);
ListCell* lc = NULL;
Bitmapset* subparamids = NULL;
/* Recurse into the testexpr, but not into the Plan */
(void)finalize_primnode(subplan->testexpr, context);
/*
* Remove any param IDs of output parameters of the subplan that were
* referenced in the testexpr. These are not interesting for
* parameter change signaling since we always re-evaluate the subplan.
* Note that this wouldn't work too well if there might be uses of the
* same param IDs elsewhere in the plan, but that can't happen because
* generate_new_param never tries to merge params.
*/
foreach (lc, subplan->paramIds) {
context->paramids = bms_del_member(context->paramids, lfirst_int(lc));
}
/* Also examine args list */
(void)finalize_primnode((Node*)subplan->args, context);
/*
* Add params needed by the subplan to paramids, but excluding those
* we will pass down to it.
*/
subparamids = bms_copy(plan->extParam);
foreach (lc, subplan->parParam) {
subparamids = bms_del_member(subparamids, lfirst_int(lc));
}
context->paramids = bms_join(context->paramids, subparamids);
return false; /* no more to do here */
}
return expression_tree_walker(node, (bool (*)())finalize_primnode, (void*)context);
}
/*
* SS_make_initplan_from_plan - given a plan tree, make it an InitPlan
*
* The plan is expected to return a scalar value of the given type/collation.
* We build an EXPR_SUBLINK SubPlan node and put it into the initplan
* list for the current query level. A Param that represents the initplan's
* output is returned.
*
* We assume the plan hasn't been put through SS_finalize_plan.
*/
Param* SS_make_initplan_from_plan(
PlannerInfo* root, Plan* plan, Oid resulttype, int32 resulttypmod, Oid resultcollation)
{
SubPlan* node = NULL;
Param* prm = NULL;
/*
* We must run SS_finalize_plan(), since that's normally done before a
* subplan gets put into the initplan list. Tell it not to attach any
* pre-existing initplans to this one, since they are siblings not
* children of this initplan. (This is something else that could perhaps
* be cleaner if we did extParam/allParam processing in setrefs.c instead
* of here? See notes for materialize_finished_plan.)
*/
/*
* Build extParam/allParam sets for plan nodes.
*/
SS_finalize_plan(root, plan, false);
/*
* Add the subplan and its PlannerInfo to the global lists.
*/
root->glob->subplans = lappend(root->glob->subplans, plan);
root->glob->subroots = lappend(root->glob->subroots, root);
/*
* Create a SubPlan node and add it to the outer list of InitPlans. Note
* it has to appear after any other InitPlans it might depend on (see
* comments in ExecReScan).
*/
node = makeNode(SubPlan);
node->subLinkType = EXPR_SUBLINK;
get_first_col_type(plan, &node->firstColType, &node->firstColTypmod, &node->firstColCollation);
node->plan_id = list_length(root->glob->subplans);
root->init_plans = lappend(root->init_plans, node);
/*
* The node can't have any inputs (since it's an initplan), so the
* parParam and args lists remain empty.
*/
cost_subplan(root, node, plan);
/*
* Make a Param that will be the subplan's output.
*/
prm = generate_new_param(root, resulttype, resulttypmod, resultcollation);
node->setParam = list_make1_int(prm->paramid);
/* Label the subplan for EXPLAIN purposes */
node->plan_name = (char*)palloc(PLANNAMELEN);
errno_t errorno = EOK;
errorno = sprintf_s(node->plan_name, PLANNAMELEN, "InitPlan %d (returns $%d)", node->plan_id, prm->paramid);
securec_check_ss(errorno, "", "");
return prm;
}
#ifdef STREAMPLAN
/*
* convert_multi_count_distinct - Given a parse tree, convert it to target
* parse tree if there's multi count(distinct) exprs.
*
* Since we can't support pull down of multi count(distinct) query, we should
* change it to multi subqueries, with one count(distinct) expr in each subquery.
* Then multi subqueries should be joined to the final query.
*/
void convert_multi_count_distinct(PlannerInfo* root)
{
Query* parse = root->parse;
AggClauseCosts agg_costs;
ListCell* lc = NULL;
ListCell* lc2 = NULL;
ListCell* lc3 = NULL;
List* group_exprs = NIL;
List* target_list = NIL;
List* fromlist = NIL;
List* new_tlist = parse->targetList;
List* tlist = NIL;
Node* quals = NULL;
Node* havingquals = parse->havingQual;
int resno = 1;
int i;
List* join_exprs = NIL;
List* rtable = NIL;
Oid* eq_op = NULL;
Oid* collation = NULL;
List* orig_target_list = NIL;
List* varlist = NIL;
List* simplevarlist = NIL;
List* joinvarlist = NIL;
if (parse->groupClause != NIL) {
if (!u_sess->attr.attr_sql.enable_hashagg) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Multi count(distinct) convert failure reason]: Enable_hashagg disabled."))));
return;
}
if (!grouping_is_hashable(parse->groupClause)) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg(
"[Multi count(distinct) convert failure reason]: Group by columns is not hash supported."))));
return;
}
}
/*
* Wo don't handle the query if it contains EC/random functions, because the EC/random
* func may be executed more than once. But the results of EC/random func is volatile, that may
* cause the query's result incorrect.
*/
contain_func_context context =
init_contain_func_context(list_make4_oid(ECEXTENSIONFUNCOID, ECHADOOPFUNCOID, RANDOMFUNCOID, NEXTVALFUNCOID));
if (contains_specified_func((Node*)parse, &context)) {
char* func_name = get_func_name(((FuncExpr*)linitial(context.func_exprs))->funcid);
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Multi count(distinct) convert failure reason]: %s functions contained.", func_name))));
pfree_ext(func_name);
list_free_ext(context.funcids);
context.funcids = NIL;
list_free_ext(context.func_exprs);
context.func_exprs = NIL;
return;
}
list_free_ext(context.funcids);
context.funcids = NIL;
/* If there are agg levelsup > 0 or sublink, count_agg_clauses doesn't handle it, so disable this */
if (contain_specified_agg_clause((Node*)parse->targetList) || contain_specified_agg_clause(parse->havingQual)) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg(
"[Multi count(distinct) convert failure reason]: Expr sublink or agg levelsup > 0 contained."))));
return;
}
/* check if multi count(distinct) conversion is needed */
errno_t errorno = EOK;
errorno = memset_s(&agg_costs, sizeof(AggClauseCosts), '\0', sizeof(AggClauseCosts));
securec_check(errorno, "", "");
count_agg_clauses(root, (Node*)parse->targetList, &agg_costs);
count_agg_clauses(root, parse->havingQual, &agg_costs);
if (list_length(agg_costs.exprAggs) <= 1 || agg_costs.hasDnAggs || agg_costs.numOrderedAggs != 0 ||
agg_costs.unhashable) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Multi count(distinct) convert failure reason]: With dn agg or ordered agg or unhashable "
"distinct node."))));
return;
}
/* If there are too many count(distinct), we disable the conversion */
if (parse->groupClause != NIL && list_length(agg_costs.exprAggs) > u_sess->attr.attr_sql.from_collapse_limit) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Multi count(distinct) convert failure reason]: Num of count(distinct) exceeds threshold."))));
return;
}
if (parse->groupingSets != NIL && agg_costs.hasdctDnAggs) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Multi count(distinct) convert failure reason]: With grouping sets and distinct dn aggs."))));
return;
}
/*
* refuse to convert if there is recursive CTE in rtables, since recursive CTE will be
* invoked more than once, which will be lead two problems
* 1. fail to set plan refs since CTE plan will be set more than once
* 2. CTEScan doesnot support shared-scan
*/
ListCell* rt = NULL;
foreach (rt, parse->rtable) {
RangeTblEntry* rte = (RangeTblEntry*)lfirst(rt);
if (rte->rtekind == RTE_CTE) {
int levelsup = rte->ctelevelsup;
int equal_parse = (root->parse == parse) ? 0 : 1;
PlannerInfo* cte_root = root;
while (equal_parse < levelsup) {
/* Find the query level that has the CTE */
cte_root = cte_root->parent_root;
levelsup--;
if (cte_root == NULL) {
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
errmsg("bad levelsup for CTE \"%s\"", rte->ctename)));
}
}
ListCell* lc_cte = NULL;
foreach (lc_cte, cte_root->parse->cteList) {
CommonTableExpr* cte = (CommonTableExpr*)lfirst(lc_cte);
/* refuse to convert if there is recursive CTE in rtables */
if (strcmp(cte->ctename, rte->ctename) == 0 && cte->cterecursive) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Multi count(distinct) convert failure reason]: With recursive CTE."))));
return;
}
}
}
}
int group_groupId_len = 0;
/* We need will groupingid append to targetlist and do equal operaotr to Ap function. */
if (parse->groupClause) {
if (parse->groupingSets) {
group_groupId_len = list_length(parse->groupClause) + 1;
} else {
group_groupId_len = list_length(parse->groupClause);
}
}
/* make group exprs for group by clause */
if (parse->groupClause != NIL) {
eq_op = (Oid*)palloc(sizeof(Oid) * group_groupId_len);
collation = (Oid*)palloc(sizeof(Oid) * group_groupId_len);
i = 0;
foreach (lc, parse->groupClause) {
SortGroupClause* clause = (SortGroupClause*)lfirst(lc);
TargetEntry* tle = get_sortgroupclause_tle(clause, parse->targetList);
if (tle == NULL)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
(errmsg("Fail to get sort group clause."))));
TargetEntry* new_tle = (TargetEntry*)copyObject(tle);
if (parse->groupingSets || (!check_var_nonnullable(parse, (Node*)tle->expr)))
root->join_null_info = lappend_int(root->join_null_info, i + 1);
new_tle->resno = i + 1;
new_tle->resjunk = false;
if (new_tle->resname == NULL)
new_tle->resname = "?column?";
eq_op[i] = clause->eqop;
collation[i] = exprCollation((Node*)tle->expr);
group_exprs = lappend(group_exprs, new_tle);
i++;
}
if (parse->groupingSets) {
GroupingId* groupId = makeNode(GroupingId);
TargetEntry* tle = makeTargetEntry((Expr*)groupId, list_length(group_exprs) + 1, "groupingid", false);
group_exprs = lappend(group_exprs, tle);
eq_op[i] = INT4EQOID;
collation[i] = 0;
}
}
/*
* Invoke make_agg_var_list() to generate all agg expressions into tlist
*
* Before do that, we have to unify the var node processing in "targetlist",
* "havingquals", "groupexprs", we need try to replace single-table var node
* with join vars, otherwise in multi count-distinct optimization can not be
* correctly processed e.g
*
* create table t1(a1,b1,c1); --- a1:var(1,1) b1:var(1,2) c1:var(1,3)
* create table t2(a2,b2,c2); --- a1:var(2,1) b1:var(2,2) c1:var(2,3)
* t1 join t2 var(3,xx)
*
* select a1, <<< replace to var(3,1)
* count(distinct b1), <<< replace to var(3,2)
* count(distinct b2) <<< replace to var(3,5)
* from t1 join t2 on t1.c1 = t2.c2
* group by t1.a1
*/
{
foreach (lc, parse->targetList) {
TargetEntry* tent = (TargetEntry*)lfirst(lc);
/*
* For joined vars in join expr, we need to find original table vars, since
* it can be used in having clause, and we should replace single table var
* with join var We should traverse into each expr to find join expr, and then
* find its original vars. We concat the original vars and join vars into
* a list, and use them to replace original vars in having quals first
*/
List* simplevars = pull_var_clause(
(Node*)tent->expr, PVC_RECURSE_AGGREGATES, PVC_RECURSE_PLACEHOLDERS, PVC_RECURSE_SPECIAL_EXPR, true);
ListCell* newcell = NULL;
foreach (newcell, simplevars) {
Var* joinvar = (Var*)lfirst(newcell);
Index varno = joinvar->varno;
AttrNumber varattno = joinvar->varattno;
/* skip vars from upper level, since they are treated as const */
if (joinvar->varlevelsup > 0)
continue;
(void)get_real_rte_varno_attno(parse, &varno, &varattno);
if (varno != joinvar->varno || varattno != joinvar->varattno) {
Var* newVar = (Var*)copyObject(joinvar);
newVar->varno = varno;
newVar->varattno = varattno;
newVar->varnoold = varno;
newVar->varoattno = varattno;
simplevarlist = lappend(simplevarlist, newVar);
joinvarlist = lappend(joinvarlist, joinvar);
}
}
list_free_ext(simplevars);
}
/* Replace the final targetlist with new vars from subqueries */
if (simplevarlist != NIL && joinvarlist != NIL) {
/* Replace base table var with join var (if possible) in targetlist */
new_tlist = (List*)replace_node_clause(
(Node*)new_tlist, (Node*)simplevarlist, (Node*)joinvarlist, RNC_COPY_NON_LEAF_NODES);
/* Replace base table var with join var (if possible) in havingquals */
havingquals =
replace_node_clause(havingquals, (Node*)simplevarlist, (Node*)joinvarlist, RNC_COPY_NON_LEAF_NODES);
/* Replace base table var with join var (if possible) in grouping expressions */
group_exprs = (List*)replace_node_clause(
(Node*)group_exprs, (Node*)simplevarlist, (Node*)joinvarlist, RNC_COPY_NON_LEAF_NODES);
}
}
tlist = make_agg_var_list(root, new_tlist, NULL);
/*
* At this point tlist is [group-by-col] [aggref] [aggref]
* Remove group-by-col from tlist to [aggref] [aggref]
*/
foreach (lc, group_exprs) {
TargetEntry* tle = (TargetEntry*)lfirst(lc);
foreach (lc2, tlist) {
Expr* expr = (Expr*)lfirst(lc2);
if (IsA(expr, TargetEntry)) {
if (equal(tle->expr, ((TargetEntry*)expr)->expr)) {
tlist = list_delete_ptr(tlist, expr);
break;
}
} else {
if (equal(tle->expr, expr)) {
tlist = list_delete_ptr(tlist, expr);
break;
}
}
}
}
/* Make the subqueries, and then join them */
foreach (lc, agg_costs.exprAggs) {
Aggref* node = (Aggref*)lfirst(lc);
RangeTblEntry* rte = NULL;
RangeTblRef* rtr = NULL;
int rtindex;
Query* partial_query = makeNode(Query);
partial_query->commandType = CMD_SELECT;
partial_query->canSetTag = true;
partial_query->rtable = (List*)copyObject(parse->rtable);
partial_query->jointree = (FromExpr*)copyObject(parse->jointree);
partial_query->groupClause = (List*)copyObject(parse->groupClause);
partial_query->hasAggs = true;
partial_query->groupingSets = parse->groupingSets ? (List*)copyObject(parse->groupingSets) : NIL;
partial_query->constraintDeps = parse->constraintDeps;
partial_query->hintState = (HintState*)copyObject(parse->hintState);
partial_query->hasSubLinks = parse->hasSubLinks;
partial_query->hasRowSecurity = parse->hasRowSecurity;
/* CTEs may be inlined as subqueries, only inherit CTEs with non-zero refcounts */
ListCell* lcCte = NULL;
partial_query->cteList = NIL;
foreach(lcCte, parse->cteList) {
CommonTableExpr* cte = (CommonTableExpr*)lfirst(lcCte);
if (cte->cterefcount > 0) { /* neither inlined nor ignored */
partial_query->cteList = lappend(partial_query->cteList, cte);
}
}
/*
* For the non-last expr, we generate count(distinct) expressions related to
* it as the targetlist, and remove them from tlist. For the last expr, just use
* the left expressions as targetlist
*/
if (lc != list_tail(agg_costs.exprAggs)) {
target_list = NIL;
for (lc2 = list_head(tlist); lc2 != NULL; lc2 = lc3) {
Aggref* n = (Aggref*)lfirst(lc2);
lc3 = lnext(lc2);
if (IsA(n, Aggref) && n->aggdistinct != NIL) {
TargetEntry* tle = (TargetEntry*)linitial(n->args);
if (equal(tle->expr, node)) {
tlist = list_delete_ptr(tlist, n);
target_list = lappend(target_list, n);
}
}
}
} else
target_list = tlist;
/* Add all the same agg expressions to the subquery's targetlist */
resno = list_length(group_exprs) + 1;
foreach (lc2, target_list) {
Node* n = (Node*)lfirst(lc2);
foreach (lc3, new_tlist) {
TargetEntry* tle = (TargetEntry*)lfirst(lc3);
if (equal(tle->expr, n)) {
TargetEntry* new_tle = flatCopyTargetEntry(tle);
new_tle->expr = (Expr*)n;
new_tle->resno = resno;
resno++;
new_tle->resjunk = false;
if (new_tle->resname == NULL)
new_tle->resname = "?column?";
lfirst(lc2) = new_tle;
break;
}
}
if (!IsA(lfirst(lc2), TargetEntry))
lfirst(lc2) = makeTargetEntry((Expr*)n, resno++, "?column?", false);
}
partial_query->targetList = list_concat((List*)copyObject(group_exprs), target_list);
#ifdef ENABLE_MULTIPLE_NODES
/* Set can_push flag of query. */
mark_query_canpush_flag((Node *) partial_query);
#endif
/* Generate subquery rte and add it to the range tables */
rte = addRangeTableEntryForSubquery(NULL, partial_query, makeAlias("subquery", NIL), false, true);
rtable = lappend(rtable, rte);
rtindex = list_length(rtable);
rtr = makeNode(RangeTblRef);
rtr->rtindex = rtindex;
fromlist = lappend(fromlist, rtr);
/* Generate join clauses for the join between subqueries */
i = 0;
foreach (lc2, partial_query->targetList) {
TargetEntry* tent = (TargetEntry*)lfirst(lc2);
Var* var = NULL;
var = makeVarFromTargetEntry(rtindex, tent);
if (i < list_length(group_exprs)) {
if (lc == list_head(agg_costs.exprAggs)) {
join_exprs = lappend(join_exprs, var);
/* Construct old and new expr to do replacement in having clause */
orig_target_list = lappend(orig_target_list, tent->expr);
varlist = lappend(varlist, var);
} else {
Node *tmp_var, *qual_item;
lc3 = (i == 0) ? list_head(join_exprs) : lnext(lc3);
tmp_var = (Node*)lfirst(lc3);
qual_item = (Node*)make_opclause(eq_op[i],
BOOLOID, /* opresulttype */
false, /* opretset */
(Expr*)copyObject(tmp_var),
(Expr*)copyObject(var),
InvalidOid,
collation[i]);
quals = make_and_qual(quals, qual_item);
}
} else {
orig_target_list = lappend(orig_target_list, tent->expr);
varlist = lappend(varlist, var);
}
i++;
}
}
new_tlist =
(List*)replace_node_clause((Node*)new_tlist, (Node*)orig_target_list, (Node*)varlist, RNC_COPY_NON_LEAF_NODES);
havingquals = replace_node_clause(havingquals, (Node*)orig_target_list, (Node*)varlist, RNC_COPY_NON_LEAF_NODES);
quals = make_and_qual(quals, havingquals);
list_free_ext(orig_target_list);
list_free_ext(varlist);
/* Now change var levels up if there's sublink in it, do it after rewrite node substitution */
IncrementVarSublevelsUp_rtable(rtable, 1, 0);
list_free_deep(parse->rtable);
/* don't free parse->targetList becaused it may be refereced in set operations */
parse->havingQual = NULL;
parse->targetList = new_tlist;
parse->jointree = makeFromExpr(fromlist, quals);
parse->rtable = rtable;
parse->cteList = NIL;
parse->hasAggs = false;
parse->hasSubLinks = false;
parse->hasRowSecurity = false;
list_free_deep(parse->groupingSets);
parse->groupingSets = NULL;
if (parse->groupClause != NIL) {
list_free_deep(parse->groupClause);
list_free_deep(group_exprs);
pfree_ext(eq_op);
pfree_ext(collation);
parse->groupClause = NIL;
}
/* Delete hintState. */
if (parse->hintState != NULL) {
HintStateDelete(parse->hintState);
pfree_ext(parse->hintState);
parse->hintState = NULL;
}
}
#endif
static bool pull_sublink_clause_walker(Node* node, pull_node_clause* context)
{
if (node == NULL)
return false;
switch (nodeTag(node)) {
case T_NullTest:
if (context->flag & PE_NULLTEST) {
context->nodeList = lappend(context->nodeList, node);
return false;
}
break;
case T_CoalesceExpr:
case T_CaseExpr:
case T_FuncExpr:
break;
case T_NullIfExpr:
if (!context->recurse) {
return false;
}
break;
case T_BoolExpr: {
/* Traversion will ceased when return true */
if (((BoolExpr*)node)->boolop == NOT_EXPR) {
if (context->flag & PE_NOTCLAUSE) {
context->nodeList = lappend(context->nodeList, node);
}
if (!context->recurse) {
return false;
}
}
break;
}
case T_OpExpr:
{
if (context->flag & PE_OPEXPR) {
context->nodeList = lappend(context->nodeList, node);
return false;
}
break;
}
case T_SubLink:
context->nodeList = lappend(context->nodeList, node);
context->nameList = lappend(context->nameList, context->name);
return false;
case T_TargetEntry:
{
TargetEntry *entry= (TargetEntry *)node;
context->name = entry->resname;
break;
}
default:
break;
}
return expression_tree_walker(node, (bool (*)())pull_sublink_clause_walker, (void*)context);
}
/* @Describe - Get sublink to list.
*
* @in node - input node expr.
* @in skipOpExpr - mark if skip expr_sublink.
*
* @return - sublink list.
*/
List *pull_sublink(Node *node, int flag, bool is_name, bool recurse)
{
pull_node_clause context;
context.nodeList = NIL;
context.nameList = NIL;
context.recurse = recurse;
context.flag = flag;
context.name = NULL;
(void)pull_sublink_clause_walker(node, &context);
if (is_name) {
return context.nameList;
}
return context.nodeList;
}
/*
* @Description: Get all opExpr.
* @in node - source node
* @in context - store op expr.
*/
static bool pull_opExpr_clause_walker(Node* node, pull_node_clause* context)
{
if (node == NULL) {
return false;
}
if (IsA(node, OpExpr)) {
context->nodeList = lappend(context->nodeList, node);
return false;
}
return expression_tree_walker(node, (bool (*)())pull_opExpr_clause_walker, (void*)context);
}
/*
* @Description: Get all opExpr.
* @in node - source node.
* @return - opExpr list.
*/
List* pull_opExpr(Node* node)
{
pull_node_clause context;
context.nodeList = NIL;
context.flag = PE_OPEXPR;
(void)pull_opExpr_clause_walker(node, &context);
return context.nodeList;
}
/*
* @Description: Get all aggrefs.
* @in node - source node
* @in context - store aggrefs.
*/
static bool pull_aggref_clause_walker(Node* node, pull_node_clause* context)
{
if (node == NULL) {
return false;
}
if (IsA(node, Aggref)) {
context->nodeList = lappend(context->nodeList, node);
return false;
}
return expression_tree_walker(node, (bool (*)())pull_aggref_clause_walker, (void*)context);
}
/*
* @Description: Get all aggrefs.
* @in node - source node.
* @return - aggrefs list.
*/
List* pull_aggref(Node* node)
{
pull_node_clause context;
context.nodeList = NIL;
context.flag = PE_AGGREF;
(void)pull_aggref_clause_walker(node, &context);
return context.nodeList;
}
/* get_equal_operates
* get equal that one size include all var is level up other include all var is not level up, when
* two size all include level up var, return false, this qual can not pull
* up.
*/
static bool get_equal_operates(OpExpr* qual, List** pullUpQual, bool paramAllowed)
{
List* qualVarList = NULL;
ListCell* lc = NULL;
int levelUp[2] = {-1, -1};
int i = 0;
foreach (lc, qual->args) {
Node* node = (Node*)lfirst(lc);
qualVarList =
pull_var_clause(node, PVC_REJECT_AGGREGATES, PVC_REJECT_PLACEHOLDERS, PVC_RECURSE_SPECIAL_EXPR, true);
bool isfirst = true;
ListCell* lc2 = NULL;
foreach (lc2, qualVarList) {
Var* var = (Var*)lfirst(lc2);
if (isfirst) {
levelUp[i] = var->varlevelsup;
} else {
if ((Index)levelUp[i] != var->varlevelsup) {
return false;
}
}
isfirst = false;
}
/* Can not volatile functions */
if (levelUp[i] == 0 && contain_volatile_functions(node)) {
return false;
}
i++;
}
/* Both sides of args include difference level vars */
if ((levelUp[0] == 1 && levelUp[1] == 0) || (levelUp[0] == 0 && levelUp[1] == 1)) {
Oid leftArgType = exprType((Node*)linitial(qual->args));
if (paramAllowed &&
(op_hashjoinable(qual->opno, leftArgType) || op_mergejoinable(qual->opno, leftArgType))) {
*pullUpQual = lappend(*pullUpQual, qual);
} else {
return false;
}
} else if ((levelUp[0] == 0 && levelUp[1] == 0) || (levelUp[0] == 0 && levelUp[1] == -1) ||
(levelUp[0] == -1 && levelUp[1] == 0) || (levelUp[0] == -1 && levelUp[1] == -1)) {
/* Only include this level vars, unnecessary to pull up, no append qual to pullUpQual */
return true;
} else {
/*
* All var is level up var, can not pull up otherwise can lead to result error.
* e.g. include or_clause select.
*/
return false;
}
return true;
}
/*
* @Description: Judge this node is equal exprs and be connected by and_exprs.
* @in node - Need judge node.
* return - If this node is equal exprs and be connected by and_exprs return true else return false.
*/
static bool equal_expr(Node* node)
{
if (node == NULL) {
return false;
}
switch (nodeTag(node)) {
case T_OpExpr: {
OpExpr* expr = (OpExpr*)node;
Oid leftArgType = exprType((Node*)linitial(expr->args));
if (!op_hashjoinable(expr->opno, leftArgType) && !op_mergejoinable(expr->opno, leftArgType)) {
return false;
}
break;
}
case T_BoolExpr: {
if (and_clause(node)) {
BoolExpr* andExpr = (BoolExpr*)node;
ListCell* lc = NULL;
foreach (lc, andExpr->args) {
Node* qual = (Node*)lfirst(lc);
if (!equal_expr(qual)) {
return false;
}
}
} else {
return false;
}
break;
}
default: {
return false;
}
}
return true;
}
/*
* Check if there is a range table entry of type func expr whose arguments
* are correlated
*/
static bool has_correlation_in_rte(List* rtable)
{
ListCell* lc_rte = NULL;
foreach (lc_rte, rtable) {
RangeTblEntry* rte = (RangeTblEntry*)lfirst(lc_rte);
if (rte->funcexpr != NULL && contain_vars_of_level_or_above(rte->funcexpr, 1)) {
return true;
}
}
return false;
}
/* judge_OpExpr_pullUp
* Judge this opexpr which include sublink if can pull up.
*/
static bool safe_convert_EXPR(PlannerInfo *root, Node *clause, SubLink* sublink, Relids available_rels, bool in_or_clause)
{
Relids varnos = NULL;
Relids level_up_varnos = NULL;
Query* subQuery = NULL;
bool limit1_in_sublink = false;
subQuery = (Query*)sublink->subselect;
if (subQuery->jointree->fromlist == NULL) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Expr sublink pull up failure reason]: Subquery's fromlist is null."))));
return false;
}
/* Can not support gropuing clause*/
if (subQuery->cteList ||
subQuery->hasWindowFuncs ||
subQuery->hasModifyingCTE ||
subQuery->havingQual ||
subQuery->groupingSets ||
subQuery->groupClause ||
subQuery->limitOffset ||
subQuery->rowMarks ||
subQuery->distinctClause ||
subQuery->windowClause) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Expr sublink pull up failure reason]: Subquery includes cte, windowFun, havingQual, group, "
"limitoffset, distinct or rowMark."))));
return false;
}
/* Only handle limit 1. */
if (subQuery->limitCount) {
Node *estLimit = NULL;
int64 limitCnt = 0;
/*
* Check whether the limit field exists in the sublink and whether
* the value of the limit field is 1.
*/
estLimit = eval_const_expressions(NULL, subQuery->limitCount);
if (estLimit && IsA(estLimit, Const)) {
limitCnt = (((Const *) estLimit)->constisnull) ? 0 :
DatumGetInt64(((Const *) estLimit)->constvalue);
} else {
limitCnt = 0;
}
if (limitCnt != 1) {
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Expr sublink pull up failure reason]: limit count of subquery is't equal to 1."))));
return false;
} else {
limit1_in_sublink = true;
}
}
/*
* In the case of without agg, we can only pull up sublink when we have limit 1 or
* unique_check which is not in or clause.
*/
if (!subQuery->hasAggs) {
if (!(limit1_in_sublink || (((unsigned int)u_sess->attr.attr_sql.rewrite_rule & SUBLINK_PULLUP_WITH_UNIQUE_CHECK) && permit_from_rewrite_hint(root, SUBLINK_PULLUP_WITH_UNIQUE_CHECK)))) {
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Expr sublink pull up failure reason]: with no agg and don't have limit1 or unique check."))));
return false;
} else if (in_or_clause) {
/* We will remove this restriction after support pull up no agg in or clause in the near future. */
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Expr sublink pull up failure reason]: with no agg in or clause can not pull up temporarily."))));
return false;
}
}
/* Targetlist of subquery can only include one element without junk attribute*/
int tle_without_junk_number = 0;
ListCell* lc = NULL;
foreach (lc, subQuery->targetList) {
TargetEntry* tle = (TargetEntry*)lfirst(lc);
if (!(tle->resjunk)) {
tle_without_junk_number++;
}
}
if (tle_without_junk_number != 1) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Expr sublink pull up failure reason]: Subquery targetlist contains more than one element "
"without the junk attribute."))));
return false;
}
/* No set operations in the subquery */
if (subQuery->setOperations) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Expr sublink pull up failure reason]: Subquery includes set operation."))));
return false;
}
varnos = pull_varnos(clause, 0, true);
/* Varnos in op need belong to available_rels otherwise it can not be pulled up */
if (!bms_is_subset(varnos, available_rels)) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg(
"[Expr sublink pull up failure reason]: Not all the varnos of opClause are in available_rels."))));
return false;
}
/* Sublink qual must be correlations in the WHERE clause */
level_up_varnos = pull_varnos(subQuery->jointree->quals, 1, true);
if ((bms_is_empty(level_up_varnos) || !bms_is_subset(level_up_varnos, available_rels)) &&
!(ENABLE_SUBLINK_PULLUP_ENHANCED() && permit_from_rewrite_hint(root, SUBLINK_PULLUP_ENHANCED))) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg(
"[Expr sublink pull up failure reason]: Sublink is uncorrelated or refer to unavailable rels."))));
return false;
}
/* Targetlist can not include level up >= 1 vars */
if (contain_vars_of_level_or_above((Node*)subQuery->targetList, 1)) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Expr sublink pull up failure reason]: Sublink targetlist includes var with levelup which is "
"greater than 0."))));
return false;
}
/* Target can not include volatile function */
if (contain_volatile_functions((Node*)subQuery->targetList)) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Expr sublink pull up failure reason]: Sublink targetlist includes volatile functions."))));
return false;
}
if (expression_returns_set((Node*)subQuery->targetList)) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Expr sublink pull up failure reason]: Sublink targetlist returns a set."))));
return false;
}
/* If deeply correlated, don't bother, in other words this subquery include another sublink and
* which include leave up gt 1 var.
*/
if (contain_vars_of_level_or_above((Node*)subQuery, 2)) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Expr sublink pull up failure reason]: Subquery includes levelup greater than 1."))));
return false;
}
if (has_correlation_in_rte(subQuery->rtable)) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Expr sublink pull up failure reason]: Subquery includes range table entry of type func expr "
"whose arguments are correlated."))));
return false;
}
/*
* Disable pullup sublink for fast query shipping plan or stream plan with replicated table, as
* these scenarios don't need stream operator, so we can use index plan to accelerate the executor.
* Notice : We don't know whether have index or whether in TP scenario ,so we use rewrite_rule to control.
*/
if ((((unsigned int)u_sess->attr.attr_sql.rewrite_rule & SUBLINK_PULLUP_DISABLE_REPLICATED) &&
permit_from_rewrite_hint(root, SUBLINK_PULLUP_DISABLE_REPLICATED)) &&
(IS_PGXC_DATANODE || (IS_STREAM_PLAN && all_replicate_table(subQuery)))) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Expr sublink pull up failure reason]: Sublink pull up of replicated table is disabled."))));
return false;
}
return true;
}
/* append_target_and_group
* Append node to targetlist and group by clause
*/
static void append_target_and_group(PlannerInfo *root, Query* subQuery, Node* node)
{
Oid sortop = InvalidOid;
Oid eqop = InvalidOid;
bool hashable = InvalidOid;
TargetEntry* tle = NULL;
SortGroupClause* grpcl = NULL;
int len = list_length(subQuery->targetList) + 1;
bool find = false;
if (ENABLE_PRED_PUSH_ALL(root)) {
ListCell* lc = NULL;
int pos = 1;
foreach (lc, subQuery->targetList) {
TargetEntry* tge = (TargetEntry*)lfirst(lc);
if (IsA(tge->expr, Var) && equal(tge->expr, node)) {
len = pos;
tge->ressortgroupref = len;
find = true;
break;
}
pos++;
}
}
if (!find)
{
/* Append this parameter to subquery targestlist*/
tle = makeTargetEntry((Expr*)node, len, pstrdup("?column?"), false);
tle->ressortgroupref = len;
subQuery->targetList = lappend(subQuery->targetList, tle);
}
/* This node need participate group of subquery. determine the eqop and optional sortop
*/
get_sort_group_operators(exprType(node), false, true, false, &sortop, &eqop, NULL, &hashable);
grpcl = makeNode(SortGroupClause);
grpcl->tleSortGroupRef = len;
grpcl->eqop = eqop;
grpcl->sortop = sortop;
grpcl->nulls_first = false;
grpcl->hashable = hashable;
subQuery->groupClause = lappend(subQuery->groupClause, grpcl);
}
static bool get_pullUp_equal_expr_internal(JoinExpr* je, List** pullUpQual, bool paramAllowed)
{
if(!get_pullUp_equal_expr(je->quals, pullUpQual, paramAllowed)) {
return false;
}
if(!get_pullUp_equal_expr(je->larg, pullUpQual, paramAllowed)) {
return false;
}
if(!get_pullUp_equal_expr(je->rarg, pullUpQual, paramAllowed)) {
return false;
}
return true;
}
/* get_pullUp_equal_expr
* Sublink can be pulled up when function return true and pullUpQual is not null.
* pullUpQual include all need pull up equal operator.
*/
static bool get_pullUp_equal_expr(Node* node, List** pullUpQual, bool paramAllowed)
{
if (node == NULL) {
return true;
}
switch (nodeTag(node)) {
case T_FromExpr: {
FromExpr* fromExpr = (FromExpr*)node;
ListCell* lc = NULL;
foreach (lc, fromExpr->fromlist) {
Node* jtree = (Node*)lfirst(lc);
if (!get_pullUp_equal_expr(jtree, pullUpQual, paramAllowed)) {
return false;
}
}
if (!get_pullUp_equal_expr(fromExpr->quals, pullUpQual, paramAllowed)) {
return false;
}
break;
}
case T_JoinExpr: {
JoinExpr* je = (JoinExpr*)node;
if (je->jointype != JOIN_INNER) {
/*
* Supports the promotion of sublinks that contain related columns
* in the where condition of outer join. The promotion of on conditions
* of outer join does not support promotion.
*/
paramAllowed = false;
}
if (!get_pullUp_equal_expr_internal(je, pullUpQual, paramAllowed)) {
return false;
}
break;
}
case T_OpExpr: {
OpExpr* expr = (OpExpr*)node;
if (!get_equal_operates(expr, pullUpQual, paramAllowed)) {
return false;
}
break;
}
case T_BoolExpr: {
if (not_clause(node) || or_clause(node)) {
if (contain_vars_of_level_or_above(node, 1)) {
return false;
}
} else {
Assert(and_clause(node));
BoolExpr* andExpr = (BoolExpr*)node;
ListCell* lc = NULL;
foreach (lc, andExpr->args) {
Node* qual = (Node*)lfirst(lc);
if (!get_pullUp_equal_expr(qual, pullUpQual, paramAllowed)) {
return false;
}
}
}
break;
}
default: {
List* qualVarList =
pull_var_clause(node, PVC_REJECT_AGGREGATES, PVC_REJECT_PLACEHOLDERS, PVC_RECURSE_SPECIAL_EXPR, true);
ListCell* lc = NULL;
foreach (lc, qualVarList) {
Var* var = (Var*)lfirst(lc);
/*
* If other expr include level up >= 1 var, then can not pull up
* e.g. NullTest.
*/
if (var->varlevelsup >= 1) {
return false;
}
}
break;
}
}
return true;
}
/*
* Disable pullup sublink for fast query shipping plan or stream plan with replicated table, as
* these scenarios don't need stream operator, so we can use index plan to accelerate the executor.
* Notice : We don't know whether have index or whether in TP scenario ,so we use rewrite_rule to control.
*/
static bool cannot_covert_ANY(PlannerInfo *root, Query* sub_select)
{
if ((((unsigned int)u_sess->attr.attr_sql.rewrite_rule & SUBLINK_PULLUP_DISABLE_REPLICATED) &&
permit_from_rewrite_hint(root, SUBLINK_PULLUP_DISABLE_REPLICATED)) &&
(IS_PGXC_DATANODE || (IS_STREAM_PLAN && all_replicate_table(sub_select)))) {
return true;
}
return false;
}
/*
* @Description: Judge this any sublink if can pull up.
* @in sublink - sublink node.
* @in available_rels1 - available rel numbers.
*/
static bool safe_convert_ANY(PlannerInfo *root, SubLink* sublink, Relids available_rels)
{
Relids varnos = NULL;
Query* sub_select = (Query*)sublink->subselect;
if (contain_vars_of_level_or_above((Node*)sub_select, 1)) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Any sublink pull up failure reason]: Sublink includes var with levelup which is greater than 0."))));
return false;
}
if (sub_select->cteList) {
return false;
}
if (sub_select->commandType != CMD_SELECT ||
sub_select->cteList ||
sub_select->setOperations ||
sub_select->hasAggs ||
sub_select->groupingSets ||
sub_select->hasWindowFuncs ||
sub_select->hasModifyingCTE ||
sub_select->havingQual ||
sub_select->limitOffset ||
sub_select->limitCount ||
sub_select->rowMarks) {
ereport(DEBUG2,
(errmodule(MOD_OPT_REWRITE),
(errmsg("[Any sublink pull up failure reason]:"
"Sublink is not select or includes"
" cte, setop, agg, windowfunc, having, grouping, limit or rowmark."))));
return false;
}
if (expression_returns_set((Node*)sub_select->targetList)) {
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Any sublink pull up failure reason]: Sublink targetlist returns a set."))));
return false;
}
/*
* The subquery must have a nonempty jointree, else we won't have a join.
*/
if (sub_select->jointree->fromlist == NIL) {
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Any sublink pull up failure reason]: Sublink's fromlist is null."))));
return false;
}
varnos = pull_varnos(sublink->testexpr);
if (bms_is_empty(varnos)) {
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Any sublink pull up failure reason]: Sublink's outer query contains no varnos."))));
return false;
}
/*
* However, it can't refer to anything outside available_rels.
*/
if (!bms_is_subset(varnos, available_rels)) {
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Any sublink pull up failure reason]: Sublink refer to unavailable rels."))));
return false;
}
/*
* The combining operators and left-hand expressions mustn't be volatile.
*/
if (contain_volatile_functions(sublink->testexpr)) {
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Any sublink pull up failure reason]: Sublink's outer query includes volatile functions."))));
return false;
}
if (cannot_covert_ANY(root, sub_select)) {
return false;
}
return true;
}
/*
* @Description: Judge this exists sublink if can pull up.
* @in sublink - sublink node.
* @in available_rels1 - available rel numbers.
*/
static bool safe_convert_EXISTS(PlannerInfo *root, SubLink* sublink, Relids available_rels)
{
Query* subselect = (Query*)(sublink->subselect);
Node* whereClause = NULL;
Relids clause_varnos = NULL;
if (contain_vars_of_level_or_above((Node*)subselect, 2)) {
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Exists sublink pull up failure reason]: "
"Sublink includes var with levelup which is greater than 1."))));
return false;
}
/*
* Can't flatten if it contains WITH. (We could arrange to pull up the
* WITH into the parent query's cteList, but that risks changing the
* semantics, since a WITH ought to be executed once per associated query
* call.) Note that convert_ANY_sublink_to_join doesn't have to reject
* this case, since it just produces a subquery RTE that doesn't have to
* get flattened into the parent query.
*/
if (subselect->commandType != CMD_SELECT ||
subselect->cteList ||
subselect->setOperations ||
subselect->hasAggs ||
subselect->groupingSets ||
subselect->hasWindowFuncs ||
subselect->hasModifyingCTE ||
subselect->havingQual ||
subselect->limitOffset ||
subselect->limitCount ||
subselect->rowMarks) {
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Exists sublink pull up failure reason]:"
" Sublink is not select or includes"
" cte, setop, agg, windowfunc, having, grouping, limit or rowmark."))));
return false;
}
if (expression_returns_set((Node*)subselect->targetList)) {
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Exists sublink pull up failure reason]: Sublink targetlist returns a set."))));
return false;
}
/*
* The subquery must have a nonempty jointree, else we won't have a join.
*/
if (subselect->jointree->fromlist == NIL) {
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Exists sublink pull up failure reason]: Sublink's fromlist is null."))));
return false;
}
/*
* Disable pullup sublink for fast query shipping plan or stream plan with replicated table, as
* these scenarios don't need stream operator, so we can use index plan to accelerate the executor.
* Notice : We don't know whether have index or whether in TP scenario ,so we use rewrite_rule to control.
*/
if ((((unsigned int)u_sess->attr.attr_sql.rewrite_rule & SUBLINK_PULLUP_DISABLE_REPLICATED) &&
permit_from_rewrite_hint(root, SUBLINK_PULLUP_DISABLE_REPLICATED)) &&
(IS_PGXC_DATANODE || (IS_STREAM_PLAN && all_replicate_table(subselect)))) {
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Exists sublink pull up failure reason]: Sublink pull up of replicated table is disabled."))));
return false;
}
/*
* Separate out the WHERE clause. (We could theoretically also remove
* top-level plain JOIN/ON clauses, but it's probably not worth the
* trouble.)
*/
whereClause = subselect->jointree->quals;
subselect->jointree->quals = NULL;
/*
* The rest of the sub-select must not refer to any Vars of the parent
* query. (Vars of higher levels should be okay, though.)
*/
if (contain_vars_of_level((Node*)subselect, 1)) {
subselect->jointree->quals = whereClause;
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Exists sublink pull up failure reason]: "
"Sublink without whereclause refer any vars of the parent."))));
return false;
}
/*
* On the other hand, the WHERE clause must contain some Vars of the
* parent query, else it's not gonna be a join.
*/
if (!contain_vars_of_level(whereClause, 1)) {
subselect->jointree->quals = whereClause;
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Exists sublink pull up failure reason]: Sublink's whereclause have no var of parent query."))));
return false;
}
/*
* We don't risk optimizing if the WHERE clause is volatile, either.
*/
if (contain_volatile_functions(whereClause)) {
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Exists sublink pull up failure reason]: Sublink whereclause includes volatile functions."))));
subselect->jointree->quals = whereClause;
return false;
}
clause_varnos = pull_varnos(whereClause, 1, true);
if (bms_is_empty(clause_varnos) || !bms_is_subset(clause_varnos, available_rels)) {
subselect->jointree->quals = whereClause;
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Exists sublink pull up failure reason]: Sublink's whereclause refer to unavailable rels."))));
return false;
}
subselect->jointree->quals = whereClause;
return true;
}
/*
* @Description: Judge this sublink if can pull up.
* @in sunlink - SubLink node.
* @return - true say this sublink can be pulled up; false say this sublink can not pulled up.
*/
static bool safe_convert_ORCLAUSE(PlannerInfo *root, Node* clause, SubLink* sublink, Relids available_rels)
{
bool result = false;
switch (sublink->subLinkType) {
case EXISTS_SUBLINK:
result = safe_convert_EXISTS(root, sublink, available_rels);
break;
case ANY_SUBLINK:
result = safe_convert_ANY(root, sublink, available_rels);
break;
case EXPR_SUBLINK:
result = safe_convert_EXPR(root, clause, sublink, available_rels, true);
break;
default:
break;
}
return result;
}
static int get_target_idx(List *targetlist, Node* node)
{
ListCell *lc = NULL;
int pos = 1;
foreach (lc, targetlist) {
TargetEntry* tge = (TargetEntry*)lfirst(lc);
if (IsA(tge->expr, Var) && equal(tge->expr, node)) {
return pos;
}
pos++;
}
return -1;
}
static void
append_target_and_windowClause(PlannerInfo *root, Query *subQuery, Node *node, bool isRowNumberFunc)
{
ListCell *lc = NULL;
TargetEntry *tle = NULL;
SortGroupClause *sortGroupClause = NULL;
WindowClause *windowClause = NULL;
WindowFunc *rowNumerFunc = NULL;
/* Append windowFunc to subquery targetlist. */
if (subQuery->windowClause == NIL) {
windowClause = (WindowClause *) makeNode(WindowClause);
windowClause->partitionClause = NIL;
windowClause->frameOptions = FRAMEOPTION_DEFAULTS;
windowClause->winref = 1;
subQuery->windowClause = lappend(subQuery->windowClause, windowClause);
subQuery->hasWindowFuncs = true;
} else {
windowClause = (WindowClause *) linitial(subQuery->windowClause);
}
if (!isRowNumberFunc) {
/* Append this parameter to subquery targestlist. */
Oid sortOp = InvalidOid;
Oid eqOp = InvalidOid;
bool hashable = false;
int len = list_length(subQuery->targetList) + 1;
bool find = false;
if (ENABLE_PRED_PUSH_ALL(root)) {
lc = NULL;
int pos = 1;
foreach (lc, subQuery->targetList) {
TargetEntry* tge = (TargetEntry*)lfirst(lc);
if (IsA(tge->expr, Var) && equal(tge->expr, node)) {
len = pos;
tge->ressortgroupref = len;
find = true;
break;
}
pos++;
}
}
if (!find)
{
tle = makeTargetEntry((Expr*)node, len, pstrdup("?column?"), false);
tle->ressortgroupref = len;
subQuery->targetList = lappend(subQuery->targetList, tle);
}
get_sort_group_operators(exprType(node),
false, true, false,
&sortOp, &eqOp, NULL,
&hashable);
sortGroupClause = (SortGroupClause *) makeNode(SortGroupClause);
sortGroupClause->tleSortGroupRef = len;
sortGroupClause->eqop = eqOp;
sortGroupClause->sortop = sortOp;
sortGroupClause->hashable = hashable;
windowClause->partitionClause = lappend(windowClause->partitionClause, sortGroupClause);
} else {
rowNumerFunc = (WindowFunc *) makeNode(WindowFunc);
rowNumerFunc->winfnoid = ROWNUMBERFUNCOID;
rowNumerFunc->wintype = INT8OID;
rowNumerFunc->wincollid = 0;
rowNumerFunc->inputcollid = 0;
rowNumerFunc->winref = windowClause->winref;
subQuery->targetList = lappend(subQuery->targetList,
makeTargetEntry((Expr *) rowNumerFunc,
list_length(subQuery->targetList) + 1,
pstrdup("?column?"), false));
foreach(lc, subQuery->sortClause)
{
Node * subQueryOrderNode = NULL;
Node * sortGroupNode = (Node *) lfirst(lc);
subQueryOrderNode = (Node *)copyObject(sortGroupNode);
windowClause->orderClause = lappend(windowClause->orderClause, subQueryOrderNode);
}
subQuery->sortClause = NULL;
}
}
static List* get_targetList_with_resjunk(List** subList)
{
List* tmptargetList = NIL;
List* targetList_with_resjunk = NIL;
ListCell* lc = NULL;
int len = 0;
foreach (lc, *subList) {
TargetEntry* te = (TargetEntry*)lfirst(lc);
if (te->resjunk) {
targetList_with_resjunk = lappend(targetList_with_resjunk, te);
} else {
len++;
te->resno = (int16)len;
tmptargetList = lappend(tmptargetList, te);
}
}
list_free(*subList);
*subList = tmptargetList;
return targetList_with_resjunk;
}
/*
* @Description: transform this euqal expr, append one args of expr to subquery's targetlist and group clauses;
* generate not null oper.
* @in root - Per-query information for planning/optimization
* @in subQuery - sublink's subquery.
* @in pullUpEqualExpr - need pull up equal expr.
* @out quals - not null expr.
* @return - join qual.
*/
static Node* transform_equal_expr(PlannerInfo* root,
Query* subQuery,
List* pullUpEqualExpr,
Node** quals,
bool isLimit,
bool isnull)
{
int targetListLen = 0;
List* constList = NULL;
int rtindex = 0;
ListCell* lc = NULL;
Node* joinQual = NULL;
Var* var = NULL;
/*The position of subquery int rtable*/
rtindex = list_length(root->parse->rtable) + 1;
/*
* We need to extract the junk column, when isLimit is true.
* Because we will append node to targetlist, if the Junk column is not at the end,
* It'll go wrong. After apending node,we will add the junk cloumn at the end.
*/
List* targetList_with_resjunk = NIL;
if (isLimit) {
targetList_with_resjunk = get_targetList_with_resjunk(&(subQuery->targetList));
}
targetListLen = list_length(subQuery->targetList);
/* Deal with equal expr in sublink*/
foreach (lc, pullUpEqualExpr) {
Assert(IsA(lfirst(lc), OpExpr));
OpExpr* pullUpExpr = (OpExpr*)lfirst(lc);
ListCell* cell = NULL;
/*
* This equal expr need pull up, and one of parameter need append to targetList of subquery
* and participate in group of subquery.
*/
foreach (cell, pullUpExpr->args) {
Node* node = (Node*)lfirst(cell);
if (contain_vars_of_level(node, 0)) {
if (ENABLE_PRED_PUSH_ALL(root)) {
int pos = get_target_idx(subQuery->targetList, node);
if (pos != -1) {
targetListLen = pos;
}
else {
targetListLen = list_length(subQuery->targetList);
targetListLen++;
}
} else {
targetListLen++;
}
lfirst(cell) = var =
makeVar(rtindex, targetListLen, exprType(node), exprTypmod(node), exprCollation(node), 0);
/*Append node to targetlist and group by clause of subquery*/
if (isLimit) {
append_target_and_windowClause(root, subQuery, (Node*)copyObject(node), false);
} else {
append_target_and_group(root, subQuery, (Node*)copyObject(node));
}
if(quals && (*quals) == NULL) {
NullTestType nullType = isnull ? IS_NULL : IS_NOT_NULL;
*quals = (Node*)makeNullTest(nullType, (Expr*)copyObject(var));
}
}
}
/*pull up this subQuery equal qual*/
joinQual = make_and_qual((Node*)joinQual, (Node*)pullUpExpr);
constList = lappend(constList, makeBoolConst(true, false));
}
if (isLimit) {
append_target_and_windowClause(root, subQuery, NULL, true);
/* The value of SortGroupRef is incorrect because the junk column is obtained.
* After the junk column is added, the size of SortGroupRef needs to be adjusted.
*/
int len = list_length(targetList_with_resjunk);
WindowClause* windowClause = (WindowClause *) linitial(subQuery->windowClause);
foreach (lc, windowClause->partitionClause) {
SortGroupClause* sortGroupClause = (SortGroupClause*)lfirst(lc);
ListCell* lc1 = NULL;
foreach (lc1, subQuery->targetList) {
TargetEntry* te = (TargetEntry*)lfirst(lc1);
if (sortGroupClause->tleSortGroupRef == te->ressortgroupref) {
sortGroupClause->tleSortGroupRef += (Index)len;
te->ressortgroupref += (Index)len;
break;
}
}
}
/* Append junk node to targetlist at the end. */
targetListLen = list_length(subQuery->targetList);
foreach (lc, targetList_with_resjunk) {
targetListLen++;
TargetEntry* te = (TargetEntry*)lfirst(lc);
te->resno = (int16)targetListLen;
subQuery->targetList = lappend(subQuery->targetList, te);
}
}
/* Delete qual from subquery, it will be pull up*/
subQuery->jointree = (FromExpr*)replace_node_clause((Node*)subQuery->jointree,
(Node*)pullUpEqualExpr,
(Node*)constList,
RNC_RECURSE_AGGREF | RNC_COPY_NON_LEAF_NODES);
return joinQual;
}
/*
* @Description: Get qual which only include special varno.
* @in all_quals: All quals.
* @in qual_list: Pull qual list struct.
*/
void get_varnode_qual(Node* all_quals, push_qual_context* qual_list)
{
if (all_quals == NULL) {
return;
} else if (and_clause(all_quals)) {
/* First check this and_clause. */
if (check_varno(all_quals, qual_list->varno, 0)) {
qual_list->qual_list = lappend(qual_list->qual_list, all_quals);
} else {
ListCell* l = NULL;
foreach (l, ((BoolExpr*)all_quals)->args) {
Node* cluase = (Node*)lfirst(l);
get_varnode_qual(cluase, qual_list);
}
}
} else if (or_clause(all_quals)) {
if (check_varno(all_quals, qual_list->varno, 0)) {
qual_list->qual_list = lappend(qual_list->qual_list, all_quals);
}
} else {
/* Check this qual if only include this varno. */
if (check_varno(all_quals, qual_list->varno, 0)) {
qual_list->qual_list = lappend(qual_list->qual_list, all_quals);
}
}
}
/*
* @Description: Get any-sublink left args and targetlist from pullUpEqualExpr.
* @in pullUpEqualExpr: Pull up equal exprs list.
* @in relid£º Relition id.
* @return: Args and targetlist.
*/
static List* get_left_args_and_target_expr(OpExpr* pullUpExpr, int relid)
{
Node* left_arg = NULL;
Node* targetExpr = NULL;
List* args_and_target = NIL;
if (list_length(pullUpExpr->args) == 2) {
ListCell* cell = NULL;
foreach (cell, pullUpExpr->args) {
Node* node = (Node*)lfirst(cell);
if (contain_vars_of_level(node, 0)) {
left_arg = node;
} else if (contain_vars_of_level(node, 1) && check_varno(node, relid, 1)) {
/* This node come from upper levels query, and only include this relid. */
targetExpr = node;
} else {
break;
}
}
}
if (left_arg != NULL && targetExpr != NULL) {
args_and_target = lappend(args_and_target, left_arg);
args_and_target = lappend(args_and_target, targetExpr);
}
return args_and_target;
}
/*
* @Description: Get can push-down's qual which is any_sublink.
* @in root: Per-query information for planning/optimization.
* @in qual_list: Only include this rel's quals.
* @in relid: Relation id.
* @n pullUpEqualExpr: Op expr list from subquery and that will be pull up.
* @out targetlist: Sublink target list.
*/
static Node* build_op_expr(PlannerInfo* root, int relid, List* pullUpEqualExpr, List** targetlist)
{
Node* sublink_text_expr = NULL;
int resno = 1;
ListCell* lc = NULL;
List* op_args = NIL;
/* Find one op_expr. its one arg be from relid. */
foreach (lc, pullUpEqualExpr) {
OpExpr* pullUpExpr = (OpExpr*)lfirst(lc);
List* args_and_target = get_left_args_and_target_expr(pullUpExpr, relid);
if (args_and_target != NIL) {
Node* left_arg = (Node*)linitial(args_and_target);
Node* targetExpr = (Node*)lsecond(args_and_target);
OpExpr* expr = NULL;
targetExpr = (Node*)copyObject(targetExpr);
/* Var's varno must be 1 in targetExpr */
OffsetVarNodes((Node*)targetExpr, 1 - relid, 1);
/* Var's levelup must be 0 in targetExpr */
IncrementVarSublevelsUp((Node*)targetExpr, -1, 1);
(*targetlist) = lappend(*targetlist, makeTargetEntry((Expr*)targetExpr, resno, NULL, false));
/* Genarate op expr. */
left_arg = (Node*)copyObject(left_arg);
Param* param = makeNode(Param);
param->paramkind = PARAM_SUBLINK;
param->paramid = resno;
param->paramtype = exprType((Node*)targetExpr);
param->paramtypmod = exprTypmod((Node*)targetExpr);
param->paramcollid = exprCollation((Node*)targetExpr);
param->location = -1;
param->tableOfIndexTypeList = NULL;
expr = (OpExpr*)make_op(NULL, list_make1(makeString("=")), left_arg, (Node*)param, NULL, 0);
op_args = lappend(op_args, expr);
resno++;
list_free_ext(args_and_target);
}
}
if (op_args != NIL)
sublink_text_expr = (Node*)make_andclause(op_args);
return sublink_text_expr;
}
/*
* @Description: Build any sublink.
* @in root: Per-query information for planning/optimization.
* @in qual: Only include this rel's quals.
* @in relid: Relation id.
* @in pullUpEqualExpr: Op expr list from subquery and that will be pull up.
*/
static SubLink* build_any_sublink(PlannerInfo* root, List* qual_list, int relid, List* pullUpEqualExpr)
{
SubLink* sub_link = NULL;
List* targetlist = NIL;
Node* sublink_text_expr = build_op_expr(root, relid, pullUpEqualExpr, &targetlist);
if (sublink_text_expr != NULL) {
RangeTblEntry* r_table = (RangeTblEntry*)rt_fetch(relid, root->parse->rtable);
r_table = (RangeTblEntry*)copyObject(r_table);
List* qualList = (List*)copyObject(qual_list);
Node* quals_node = NULL;
ListCell* lc = NULL;
foreach (lc, qualList) {
Node* node = (Node*)lfirst(lc);
quals_node = make_and_qual(quals_node, node);
}
list_free_ext(qualList);
/* Var's varno should be 1 in qual */
OffsetVarNodes(quals_node, 1 - relid, 0);
/* Offset varno for r_table's row level security quals */
OffsetVarNodes((Node*)r_table->securityQuals, 1 - relid, 0);
Query* selectQuery = makeNode(Query);
selectQuery->commandType = CMD_SELECT;
selectQuery->targetList = targetlist;
selectQuery->rtable = list_make1(r_table);
RangeTblRef* rtr = makeNode(RangeTblRef);
rtr->rtindex = 1;
selectQuery->jointree = makeFromExpr(list_make1(rtr), quals_node);
#ifdef ENABLE_MULTIPLE_NODES
/* Set can_push flag of query. */
mark_query_canpush_flag((Node *) selectQuery);
#endif /* ENABLE_MULTIPLE_NODES */
sub_link = makeNode(SubLink);
sub_link->subLinkType = ANY_SUBLINK;
sub_link->subselect = (Node*)selectQuery;
sub_link->testexpr = (Node*)sublink_text_expr;
}
return sub_link;
}
/*
* @Description: When the opexpr sublink is converted to the left join, the converted
* filtering condition needs to be generated according to the targetlist.
* For example :
* select * from t1 where t1.a = (select count(*) from t2 where t1.b = t2.b);
*
* Rewritten form :
* select t1.* from t1 left join (select count(t2.a) as cnt, b from t2 group by t2.b)
* as tt on tt.b = t1.b where t1.a = coalesce(tt.cnt,0);.
*
* This function is used to generate 't1.a = coalesce(tt.cnt, 0)' based on count(*),
* other similar.
* @in root - PlannerInfo.
* @in rtIndex - Varno of new vars to be built.
* @in targetExpr - TargetEntry expr.
* @in subQuery - Subquery of opexpr sublink.
* @return : Filter condition.
*/
Node*
generate_filter_on_opexpr_sublink(PlannerInfo *root,
int rtIndex,
Node *targetExpr,
Query *subQuery)
{
List *varClauseList = NIL;
List *aggFuncList = NIL;
ListCell *lc = NULL;
Node *filterExpr = NULL;
Var *aggVar = NULL;
TargetEntry *aggTargetEntry = NULL;
/* Recursively iterates through targetExpr and finds the aggregate function in it. */
filterExpr = (Node *) copyObject(targetExpr);
varClauseList = pull_var_clause(filterExpr,
PVC_INCLUDE_AGGREGATES,
PVC_REJECT_PLACEHOLDERS,
PVC_RECURSE_SPECIAL_EXPR);
/* Notice, We only need agg functions. */
foreach(lc, varClauseList)
{
bool exists = false;
Node *tNode = (Node *) lfirst(lc);
if (IsA(tNode, Aggref)) {
ListCell * innerLc = NULL;
foreach(innerLc , aggFuncList) {
Node *aggFuncNode = (Node *) lfirst(innerLc);
Assert(IsA(aggFuncNode, Aggref));
if (((Aggref *) tNode)->aggfnoid == ((Aggref *) aggFuncNode)->aggfnoid &&
equal(((Aggref *) tNode)->args, ((Aggref *) aggFuncNode)->args)) {
exists = true;
break;
}
}
if (!exists) {
aggFuncList = lappend(aggFuncList, tNode);
}
}
exists = false;
}
list_free_ext(varClauseList);
if (aggFuncList == NIL) {
return (Node *)makeVar(rtIndex, 1,
exprType((Node *) targetExpr),
exprTypmod((Node *) targetExpr),
exprCollation((Node *) targetExpr),
0);
}
foreach(lc, aggFuncList) {
ListCell *innerLc = NULL;
Node *aggFuncNode = (Node *) lfirst(lc);
Node *decoratedConstraints = NULL;
Node *constNode = NULL;
Assert(((Aggref *) aggFuncNode)->agglevelsup == 0);
/*
* Try to find target entry only including this function node. If not found,
* construct a new targetEntry based on agg function node, and append it to
* the targetList of subQuery.
*/
foreach(innerLc, subQuery->targetList) {
TargetEntry *tempTargetEntry = (TargetEntry *) lfirst(innerLc);
if (equal(tempTargetEntry->expr, aggFuncNode)) {
aggTargetEntry = tempTargetEntry;
break;
}
}
/* If not found, add a new targetEntry. */
if (innerLc == NULL) {
aggTargetEntry = makeTargetEntry((Expr *) aggFuncNode,
list_length(subQuery->targetList) + 1,
pstrdup("?column?"),
false);
subQuery->targetList = lappend(subQuery->targetList, aggTargetEntry);
}
/* Construct a new aggregate var to replace the aggregate function in targetExpr. */
aggVar = makeVarFromTargetEntry(rtIndex, aggTargetEntry);
if ((((Aggref *) aggFuncNode)->aggfnoid == ANYCOUNTOID) ||
(((Aggref *) aggFuncNode)->aggfnoid == COUNTOID)) {
constNode = (Node *) makeConst(INT4OID, -1, InvalidOid, sizeof(uint32),
Int32GetDatum(0), false, true);
decoratedConstraints = (Node *) makeNode(CoalesceExpr);
((CoalesceExpr *) decoratedConstraints)->coalescecollid = InvalidOid;
((CoalesceExpr *) decoratedConstraints)->coalescetype = exprType((Node *) aggFuncNode);
((CoalesceExpr *) decoratedConstraints)->args = list_make2(aggVar, (Node *) constNode);
} else {
decoratedConstraints = (Node *) aggVar;
}
filterExpr = replace_node_clause((Node *) filterExpr,
(Node *) aggFuncNode,
(Node *) decoratedConstraints,
RNC_COPY_NON_LEAF_NODES);
}
return filterExpr;
}
/*
* @Description: Set var's varno and attno to base rel's relid and attribute number.
* @in parse: Query tree.
* @in node: Qual list.
* @in level_up: If only deal with level up var.
*/
static void set_varno_attno(Query* parse, Node* node, bool level_up)
{
List* vars =
pull_var_clause(node, PVC_RECURSE_AGGREGATES, PVC_RECURSE_PLACEHOLDERS, PVC_RECURSE_SPECIAL_EXPR, true);
ListCell* cell = NULL;
foreach (cell, vars) {
Var* var = (Var*)lfirst(cell);
/* Only set the levelup = 1 var. */
if (level_up && var->varlevelsup != 1) {
continue;
} else if (!level_up && var->varlevelsup != 0) { /* Only set the levelup = 0 var. */
continue;
}
RangeTblEntry* rte = (RangeTblEntry*)rt_fetch(var->varno, parse->rtable);
if (rte->rtekind == RTE_JOIN) {
Node* join_node = (Node*)list_nth(rte->joinaliasvars, var->varattno - 1);
if (IsA(join_node, Var)) {
Var* v = (Var*)join_node;
var->varno = v->varno;
var->varattno = v->varattno;
set_varno_attno(parse, (Node*)var, level_up);
}
}
}
list_free_ext(vars);
}
/*
* @Description: Get condition which can push down to suquery from master query.
* @in all_quals: Master query's all quals.
* @in pullUpEqualExpr: Op expr list from subquery and that will be pull up.
*/
static Node* push_down_qual(PlannerInfo* root, Node* all_quals, List* pullUpEqualExpr)
{
if (all_quals == NULL) {
return NULL;
}
List* pullUpExprList = (List*)copyObject(pullUpEqualExpr);
Node* all_quals_list = (Node*)copyObject(all_quals);
/* pullUpExprList is correlate condition, this function only should set upper levels var. */
set_varno_attno(root->parse, (Node*)pullUpExprList, true);
set_varno_attno(root->parse, (Node*)all_quals_list, false);
Relids varnos = pull_varnos((Node*)pullUpExprList, 1);
push_qual_context qual_list;
SubLink* any_sublink = NULL;
Node* push_quals = NULL;
int attnum = 0;
while ((attnum = bms_first_member(varnos)) >= 0) {
RangeTblEntry* r_table = (RangeTblEntry*)rt_fetch(attnum, root->parse->rtable);
/* This table need be base table, other not to deal. */
if (r_table->rtekind == RTE_RELATION) {
qual_list.varno = attnum;
qual_list.qual_list = NIL;
/* Get qual which only include special varno. */
get_varnode_qual(all_quals_list, &qual_list);
/* Upper query include qual which only include this attnum. */
if (qual_list.qual_list != NIL && !contain_volatile_functions((Node*)qual_list.qual_list)) {
any_sublink = build_any_sublink(root, qual_list.qual_list, attnum, pullUpExprList);
push_quals = make_and_qual(push_quals, (Node*)any_sublink);
}
list_free_ext(qual_list.qual_list);
}
}
list_free_deep(pullUpExprList);
pfree_ext(all_quals_list);
return push_quals;
}
/*
* @Description: Pull up expr sublink can pull up.
* @in root: Per-query information for planning/optimization.
* @in jtlink1: Current joinExpr.
* @in inout_quals: Op expr.
* @in sublink: Expr sublink.
* @in available_rels: Available relids.
* @out isPullUp: If pull up.
* @in all_quals: Quals.
* @return: Final join quals.
*/
Node*
convert_EXPR_sublink_to_join(PlannerInfo *root,
Node **jtlink1,
Node *inout_quals,
SubLink *sublink,
Relids *available_rels,
Node *all_quals,
const char *refname)
{
Query *subQuery = (Query *)sublink->subselect;
if (!safe_convert_EXPR(root, inout_quals, sublink, *available_rels) || has_no_expand_hint(subQuery)) {
return inout_quals;
}
/*
* Situation 1: limit 1
* For example:
* select * from t1 where t1.a = (select t2.a from t2 where t2.b = t1.b limit 1)
*/
if (!subQuery->hasAggs && subQuery->limitCount)
{
return convert_expr_sublink_with_limit_clause(root,
jtlink1,
sublink,
inout_quals,
available_rels,
all_quals, refname);
} else if (ENABLE_SUBLINK_PULLUP_ENHANCED() &&
permit_from_rewrite_hint(root, SUBLINK_PULLUP_ENHANCED) &&
safe_apply_winmagic(root, inout_quals, sublink, available_rels)) {
/*
* Situation 2: agg with winmagic
* Use windows aggregation to eliminate sublinks.
* This method only available when SUBLINK_PULLUP_ENHANCED
* is set.
*/
return convert_expr_sublink_with_winmagic(root, jtlink1, inout_quals, sublink, available_rels);
} else {
/*
* Situation 3: agg For example:
* select * from t1 where t1.a = (select avg(t2.a) from t2 where t2.b = t1.b)
* select * from t1 where t1.a = (select avg(t2.a) from t2 where t2.b = t1.b limit 1)
* select * from t1 where t1.a = (select t2.a from t2 where where t2.b = t1.b)
*/
return convert_expr_subink_with_agg_targetlist(root, jtlink1, inout_quals, sublink, available_rels, all_quals,
refname);
return NULL;
}
}
static TargetEntry* getRowNumberTargetEntry(const List *subList)
{
ListCell* lc = NULL;
foreach (lc, subList) {
TargetEntry* tle = (TargetEntry*)lfirst(lc);
if (IsA(tle->expr, WindowFunc) && ((WindowFunc*)(tle->expr))->winfnoid == ROWNUMBERFUNCOID) {
return tle;
}
}
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
(errmsg("Can't find targetEntry with rownumber window function."))));
return NULL;
}
/*
* @Description: Convert expr-sublink which targetlist does't contain agg function,
* but includes limit clause to left join.
* For example:
* select * from t1 where t1.a = (select t2.a from t2 where t2.b = t1.b
* order by t2.a limit 1)
*
* @in root - PlannerInfo.
* @in currJoinLink - Current join link.
* @in sublink - Sublink which will be pulled up.
* @in exprQual - Condition expression that contains sublink.
* @in available_rels - Available relids.
* @return : Expr node.
*/
static Node*
convert_expr_sublink_with_limit_clause(PlannerInfo *root,
Node ** currJoinLink,
SubLink *sublink,
Node *exprQual,
Relids *available_rels,
Node *all_quals, const char *refname)
{
List *pullUpEqualQuals = NIL;
ListCell *lc = NULL;
Node *joinQual = NULL;
Node *push_quals = NULL;
Node *rowNumVar = NULL;
Node *tmpExprQual = exprQual;
Query *subQuery = NULL;
Query *newSubquery = NULL;
RangeTblEntry *rte = NULL;
RangeTblRef *rtr = NULL;
Index rtIndex = 0;
Relids level_up_varnos = NULL;
subQuery = (Query *) sublink->subselect;
if (ENABLE_SUBLINK_PULLUP_ENHANCED() && permit_from_rewrite_hint(root, SUBLINK_PULLUP_ENHANCED)) {
level_up_varnos = pull_varnos(subQuery->jointree->quals, 1, true);
if (bms_is_empty(level_up_varnos) || !bms_is_subset(level_up_varnos, *available_rels)) {
return exprQual;
}
}
/*
* Check whether the conditions of the sublink meet the requirements
* of the pull. The conditions are met only when the conditions are
* all equal.
*/
if (get_pullUp_equal_expr((Node*)subQuery->jointree, &pullUpEqualQuals) &&
pullUpEqualQuals)
{
/* Guc rewrite_rule need set to magicset.*/
if (((u_sess->attr.attr_sql.rewrite_rule & MAGIC_SET) && permit_from_rewrite_hint(root, MAGIC_SET)) && !contain_subplans((Node*)subQuery->jointree))
{
/* Get can push down to subquery's quals. */
push_quals = push_down_qual(root, all_quals, pullUpEqualQuals);
}
joinQual = transform_equal_expr(root, subQuery, pullUpEqualQuals, NULL, true);
/*
* Upper-level vars in subquery will now be one level closer to their
* parent than before; in particular, anything that had been level 1
* becomes level zero.
*/
rtIndex = list_length(root->parse->rtable) + 1;
IncrementVarSublevelsUp(joinQual, -1, 1);
*available_rels = bms_add_member(*available_rels, (int)rtIndex);
if (push_quals != NULL)
{
subQuery->jointree->quals = make_and_qual(subQuery->jointree->quals, push_quals);
subQuery->hasSubLinks = true;
}
newSubquery = makeNode(Query);
newSubquery->commandType = CMD_SELECT;
newSubquery->can_push = true;
if (refname != NULL && ENABLE_PRED_PUSH_ALL(root)) {
rte = addRangeTableEntryForSubquery(NULL,
subQuery,
makeAlias(refname, NIL),
false,
false,
true);
} else {
rte = addRangeTableEntryForSubquery(NULL,
subQuery,
makeAlias("subquery", NIL),
false,
false,
true);
}
newSubquery->rtable = list_make1(rte);
newSubquery->targetList = NIL;
int tleIdx = 1;
foreach(lc, subQuery->targetList)
{
TargetEntry *te = (TargetEntry *) lfirst(lc);
if (te->resjunk) {
continue;
}
TargetEntry *newTe = NULL;
Var *newVar = makeVarFromTargetEntry(1, te);
Assert(tleIdx <= list_length(subQuery->targetList));
newTe = makeTargetEntry((Expr *) newVar, tleIdx, pstrdup("?column?"), false);
newSubquery->targetList = lappend(newSubquery->targetList, newTe);
tleIdx++;
}
rtr = makeNode(RangeTblRef);
rtr->rtindex = 1;
newSubquery->jointree = (FromExpr *) makeNode(FromExpr);
newSubquery->jointree->fromlist = list_make1(rtr);
rowNumVar = (Node *) makeVarFromTargetEntry(1, getRowNumberTargetEntry(subQuery->targetList));
newSubquery->jointree->quals = (Node *) make_opclause(INT84EQOID, BOOLOID,
false,
(Expr *) rowNumVar,
(Expr *) subQuery->limitCount,
InvalidOid,
InvalidOid);
subQuery->limitCount = NULL;
/* Replace sublink with the first targetentry expr of newSubquery. */
Var *replaceSublinkVar = makeVarFromTargetEntry(rtIndex, (TargetEntry *) linitial(newSubquery->targetList));
exprQual = replace_node_clause(exprQual,
(Node *) sublink,
(Node *) replaceSublinkVar,
RNC_RECURSE_AGGREF | RNC_COPY_NON_LEAF_NODES);
/* Add new subquery to root->ratble */
rte = addRangeTableEntryForSubquery(NULL,
newSubquery,
makeAlias("newSubquery", NIL),
false,
false,
true);
root->parse->rtable = lappend(root->parse->rtable, rte);
/*
* This qual of include sublink need be pull up, we will it replace with true here.
* For example:
* select * from t1 inner join t2 on t2.a = (select avg(t3.a) from t3 where t3.b = t2.b);
*/
if (IsA(*currJoinLink, JoinExpr)) {
((JoinExpr*)*currJoinLink)->quals = replace_node_clause(((JoinExpr*)*currJoinLink)->quals,
tmpExprQual,
makeBoolConst(true, false),
RNC_RECURSE_AGGREF | RNC_COPY_NON_LEAF_NODES);
} else if (IsA(*currJoinLink, FromExpr)) {
((FromExpr*)*currJoinLink)->quals = replace_node_clause(((FromExpr*)*currJoinLink)->quals,
tmpExprQual,
makeBoolConst(true, false),
RNC_RECURSE_AGGREF | RNC_COPY_NON_LEAF_NODES);
}
/* Make new RangeTblEntry, refference to the newSubquery created. */
rtr = (RangeTblRef *) makeNode(RangeTblRef);
rtr->rtindex = list_length(root->parse->rtable);
/* Make JoinExpr of left join. */
JoinExpr *result = NULL;
result = (JoinExpr *) makeNode(JoinExpr);
result->jointype = JOIN_LEFT;
result->quals = joinQual;
result->larg = *currJoinLink;
result->rarg = (Node *) rtr;
/*
* Add JoinExpr to rangetableentry. In subsequent processing, the left
* external connection may be converted into an internal connection.
*/
rte = addRangeTableEntryForJoin(NULL,
NIL,
result->jointype,
NIL,
result->alias,
true);
root->parse->rtable = lappend(root->parse->rtable, rte);
*currJoinLink = (Node *) result;
/* Mark query's can_push */
mark_parent_child_pushdown_flag(root->parse, newSubquery);
list_free_ext(pullUpEqualQuals);
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Sublink pull up failure reason]: Sublink need 'equal' with suitable level vars and can only combined with 'and'."))));
return exprQual;
}
else
{
list_free_ext(pullUpEqualQuals);
return exprQual;
}
}
/*
* @Description: Convert expr-sublink which targetlist contains agg function.
* For example:
* select * from t1 where t1.a = (select avg(t2.a) from t2 where t2.b = t1.b);
*
* @in root - PlannerInfo.
* @in jtlink1 - Current join link.
* @in inout_quals - Condition expression that contains sublink.
* @in sublink - Sublink which will be pulled up.
* @in available_rels - Available relids.
* @in all_quals - Quals
* @return : Expr node.
*/
static Node*
convert_expr_subink_with_agg_targetlist(PlannerInfo *root,
Node **jtlink1,
Node *inout_quals,
SubLink *sublink,
Relids *available_rels,
Node *all_quals, const char *refname)
{
int rtindex = 0;
List *pullUpEqualExpr = NIL;
Query *subQuery = NULL;
Node *joinQual = NULL;
Node *push_quals = NULL;
bool pullupUnCorrelated = false;
subQuery = (Query*)sublink->subselect;
pullupUnCorrelated = (safe_pullup_uncorrelated_sublink_where(inout_quals, subQuery, available_rels) &&
ENABLE_SUBLINK_PULLUP_ENHANCED() &&
permit_from_rewrite_hint(root, SUBLINK_PULLUP_ENHANCED));
/*
* Judge this sublink if all quals is 'equal' and it is connected by 'and', and equal expr
* one size include level up var other not include if so it can pull up or else not, and
* append need pull up equal expr in sublink to list. sublink can be pulled up where
* get_pullUp_equal_expr return true and pullUpEqualExpr is not null.
*/
if ((get_pullUp_equal_expr((Node*)subQuery->jointree, &pullUpEqualExpr) && pullUpEqualExpr) || pullupUnCorrelated)
{
/* Guc rewrite_rule need set to magicset.*/
if (((u_sess->attr.attr_sql.rewrite_rule & MAGIC_SET) && permit_from_rewrite_hint(root, MAGIC_SET)) && !contain_subplans((Node*)subQuery->jointree))
{
/* Get can push down to subquery's quals.*/
push_quals = push_down_qual(root, all_quals, pullUpEqualExpr);
}
/* Mark unique_check flag of subquery */
subQuery->unique_check = !subQuery->hasAggs;
/* Rollback to don't pull up sublink when cannot hash or in upgrade. */
if (subQuery->unique_check &&
(!CanExprHashable(pullUpEqualExpr) ||
t_thrd.proc->workingVersionNum < SUBLINKPULLUP_VERSION_NUM))
{
subQuery->unique_check = false;
list_free_ext(pullUpEqualExpr);
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Expr sublink pull up failure reason]: Only support unique check for hashable scenario."))));
return inout_quals;
}
joinQual = transform_equal_expr(root, subQuery, pullUpEqualExpr, NULL, false);
/* Pull up sublink, replace var by sublink that come from subquery. */
JoinExpr *result = NULL;
Node *tmp_opexpr = inout_quals;
Node *expr = (Node *)((TargetEntry *)linitial(subQuery->targetList))->expr;
Node *decoratedConstraints = NULL;
/* Add new rtindex of rangeTblRef, append rindex to available rel number. */
rtindex = list_length(root->parse->rtable) + 1;
*available_rels = bms_add_member(*available_rels, rtindex);
/*
* Generates filtering conditions for left join based on the targetlist of
* the subLink.
*/
decoratedConstraints = generate_filter_on_opexpr_sublink(root,
rtindex,
expr,
subQuery);
if (decoratedConstraints != NULL) {
inout_quals = replace_node_clause(inout_quals, (Node*) sublink,
decoratedConstraints, RNC_RECURSE_AGGREF | RNC_COPY_NON_LEAF_NODES);
}
/*
* Upper-level vars in subquery will now be one level closer to their
* parent than before; in particular, anything that had been level 1
* becomes level zero.
*/
IncrementVarSublevelsUp(joinQual, -1, 1);
/* This qual of include sublink need be pull up, we will it replace with true here. */
if (IsA(*jtlink1, JoinExpr)) {
((JoinExpr*)*jtlink1)->quals = replace_node_clause(((JoinExpr*)*jtlink1)->quals,
tmp_opexpr,
makeBoolConst(true, false),
RNC_RECURSE_AGGREF | RNC_COPY_NON_LEAF_NODES);
} else if (IsA(*jtlink1, FromExpr)) {
Assert(IsA(*jtlink1, FromExpr));
((FromExpr*)*jtlink1)->quals = replace_node_clause(((FromExpr*)*jtlink1)->quals,
tmp_opexpr,
makeBoolConst(true, false),
RNC_RECURSE_AGGREF | RNC_COPY_NON_LEAF_NODES);
}
if (push_quals != NULL)
{
subQuery->jointree->quals = make_and_qual(subQuery->jointree->quals, push_quals);
subQuery->hasSubLinks = true;
}
/* Append subquery to rtable*/
RangeTblEntry* rte = NULL;
if (refname != NULL && ENABLE_PRED_PUSH_ALL(root)) {
rte = addRangeTableEntryForSubquery(NULL, subQuery, makeAlias(refname, NIL), false, false, true);
} else {
rte = addRangeTableEntryForSubquery(NULL, subQuery, makeAlias("subquery", NIL), false, false, true);
}
root->parse->rtable = lappend(root->parse->rtable, rte);
/* Append rangeTblRef to fromlist. */
RangeTblRef *rtr = makeNode(RangeTblRef);
rtr->rtindex = rtindex;
result = makeNode(JoinExpr);
result->jointype = JOIN_LEFT;
result->larg = *jtlink1;
result->rarg = (Node*)rtr;
result->alias = NULL;
result->quals = joinQual;
/* Append joinExpr to rtable. */
rte = addRangeTableEntryForJoin(NULL,
NIL,
result->jointype,
NIL,
result->alias,
true);
root->parse->rtable = lappend(root->parse->rtable, rte);
*jtlink1 = (Node*) result;
/* Mark query's can_push */
mark_parent_child_pushdown_flag(root->parse, subQuery);
list_free_ext(pullUpEqualExpr);
return inout_quals;
}
else
{
list_free_ext(pullUpEqualExpr);
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Sublink pull up failure reason]: Sublink need 'equal' with suitable level vars and can only combined with 'and'."))));
return inout_quals;
}
}
/*
* @Description:
* @in root - Per-query information for planning/optimization
* @in or_clause - or clause args
* @in exists_sublink - exists sublink
* @in jtlink1 - points to the link in the jointree
* @in available_rels1 - available table index
*
* @return - Returns the replacement qual node, or NULL if the qual should be removed.
*/
void convert_OREXISTS_to_join(
PlannerInfo* root, BoolExpr* or_clause, SubLink* exists_sublink, Node** jtlink1, Relids available_rels1, bool isnull)
{
Query* subQuery = NULL;
List* pullUpEqualExpr = NULL;
Node* joinQual = NULL;
Node* whereClause = NULL;
JoinExpr* result = NULL;
Node* quals = NULL;
RangeTblEntry* rte = NULL;
if (!safe_convert_ORCLAUSE(root, NULL, exists_sublink, available_rels1)) {
return;
}
subQuery = (Query*)(exists_sublink->subselect);
if (has_no_expand_hint(subQuery)) {
return;
}
subQuery = (Query*)copyObject(subQuery);
/*
* We can throw away the targetlist, as well as any GROUP, WINDOW, DISTINCT, and ORDER BY clauses.
* These clauses is not useful, can not effect final results.
*/
subQuery->targetList = NIL;
subQuery->groupClause = NIL;
subQuery->distinctClause = NIL;
subQuery->sortClause = NIL;
subQuery->hasDistinctOn = false;
whereClause = subQuery->jointree->quals;
if (get_pullUp_equal_expr(whereClause, &pullUpEqualExpr) && pullUpEqualExpr) {
joinQual = transform_equal_expr(root, subQuery, pullUpEqualExpr, &quals, false, isnull);
/* Replace this sublink with quals which is "not null" expr.*/
or_clause = (BoolExpr*)replace_node_clause(
(Node*)or_clause, (Node*)exists_sublink, (Node*)quals, RNC_RECURSE_AGGREF | RNC_REPLACE_FIRST_ONLY);
List* l = NULL;
for (int i = 0; i < list_length(pullUpEqualExpr); i++) {
l = lappend(l, makeBoolConst(true, false));
}
/* Replace these equal exprs with const true . */
whereClause =
(Node*)replace_node_clause((Node*)whereClause, (Node*)pullUpEqualExpr, (Node*)l, RNC_RECURSE_AGGREF);
/*
* Upper-level vars in subquery will now be one level closer to their
* parent than before; in particular, anything that had been level 1
* becomes level zero.
*/
IncrementVarSublevelsUp(joinQual, -1, 1);
/* Append subquery to rtable*/
if (root->glob->sublink_counter != 0 && ENABLE_PRED_PUSH_ALL(root)) {
char *subquery_name = denominate_sublink_name(root->glob->sublink_counter);
rte = addRangeTableEntryForSubquery(NULL, subQuery, makeAlias(subquery_name, NIL), false, false, true);
} else {
rte = addRangeTableEntryForSubquery(NULL, subQuery, makeAlias("subquery", NIL), false, false, true);
}
/* Now we can attach the modified subquery rtable to the parent.*/
root->parse->rtable = lappend(root->parse->rtable, rte);
RangeTblRef* rtr = makeNode(RangeTblRef);
rtr->rtindex = list_length(root->parse->rtable);
result = makeNode(JoinExpr);
result->jointype = JOIN_LEFT;
result->quals = joinQual;
result->larg = *jtlink1;
result->rarg = (Node*)rtr;
result->alias = NULL;
*jtlink1 = (Node*)result;
/* Mark query's can_push */
mark_parent_child_pushdown_flag(root->parse, subQuery);
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Sublink pull up failure reason]: Sublink need 'equal' with suitable level vars and can only combined with 'and'."))));
list_free_ext(pullUpEqualExpr);
return;
} else {
list_free_ext(pullUpEqualExpr);
return;
}
}
/*
* @Description: add all targetlist's expr to group clauses.
* @in query - query.
*/
static void add_targetlist_to_group(Query* query)
{
AssertEreport(query->groupClause == NIL, MOD_OPT_REWRITE, "Sublink to be pulled up shouldn't have group clause");
int len = 1;
SortGroupClause* grpcl = NULL;
ListCell* lc = NULL;
foreach (lc, query->targetList) {
TargetEntry* tg = (TargetEntry*)lfirst(lc);
Node* node = (Node*)tg->expr;
Oid sortop = InvalidOid;
Oid eqop = InvalidOid;
bool hashable = InvalidOid;
get_sort_group_operators(exprType(node), false, true, false, &sortop, &eqop, NULL, &hashable);
tg->ressortgroupref = len;
grpcl = makeNode(SortGroupClause);
grpcl->tleSortGroupRef = len;
grpcl->eqop = eqop;
grpcl->sortop = sortop;
grpcl->nulls_first = false;
grpcl->hashable = hashable;
query->groupClause = lappend(query->groupClause, grpcl);
len++;
}
}
/**
* @Description remove the targetentry in targetlist whose resjunk is true.
*
* @in query - query.
*/
static void remove_target_not_in_final(Query *query)
{
List *old_targetList = NIL;
List *new_targetList = NIL;
old_targetList = query->targetList;
query->targetList = NIL;
ListCell *lc = NULL;
foreach (lc, old_targetList) {
TargetEntry *tg = (TargetEntry *)lfirst(lc);
if (tg->resjunk)
continue;
new_targetList = lappend(new_targetList, tg);
}
query->targetList = new_targetList;
}
/*
* @Description: Convert this any sublink to left join.
* @in root - Per-query information for planning/optimization.
* @in or_clause - current or clause.
* @in any_sublink - This any sublink.
* @in jtlink1 - current joinExpr
* @available_rels1 - available rel number.
*/
void convert_ORANY_to_join(
PlannerInfo* root, BoolExpr* or_clause, SubLink* any_sublink, Node** jtlink1, Relids available_rels)
{
Query* sub_select = (Query*)any_sublink->subselect;
if (has_no_expand_hint(sub_select)) {
return;
}
Query* parse = root->parse;
List* subquery_vars = NULL;
Node* test_quals = NULL;
int rtindex;
RangeTblEntry* rte = NULL;
RangeTblRef* rtr = NULL;
JoinExpr* result = NULL;
if (!safe_convert_ORCLAUSE(root, NULL, any_sublink, available_rels)) {
return;
}
sub_select = (Query*)copyObject(sub_select);
/*
* We can throw away GROUP, DISTINCT, and ORDER BY clauses.
* These clauses is not useful, can not effect final results, because targetlist can not
* include agg.
*/
sub_select->groupClause = NIL;
sub_select->distinctClause = NIL;
sub_select->sortClause = NIL;
sub_select->hasDistinctOn = false;
/* New rtable's index. */
rtindex = list_length(parse->rtable) + 1;
/*
* Build the new join's qual expression, replacing Params with these Vars.
*/
subquery_vars = generate_subquery_vars(root, sub_select->targetList, rtindex);
test_quals = convert_testexpr(root, any_sublink->testexpr, subquery_vars);
/* Judge this quals if only include 'and' and 'equal' oper. */
if (equal_expr(test_quals)) {
/* remove the target entry which will not display in the final target list . */
remove_target_not_in_final(sub_select);
/* add all targetlist to query's group clsuse. */
add_targetlist_to_group(sub_select);
TargetEntry* tg = (TargetEntry*)linitial(sub_select->targetList);
Node* node = (Node*)tg->expr;
Var* var = makeVar(rtindex, 1, exprType(node), exprTypmod(node), exprCollation(node), 0);
NullTest* nullTest = makeNullTest(IS_NOT_NULL, (Expr*)var);
/* Replace this any sublink with "not null" expr. */
or_clause =
(BoolExpr*)replace_node_clause((Node*)or_clause, (Node*)any_sublink, (Node*)nullTest, RNC_RECURSE_AGGREF | RNC_REPLACE_FIRST_ONLY);
if (root->glob->sublink_counter != 0 && ENABLE_PRED_PUSH_ALL(root)) {
char *subquery_name = denominate_sublink_name(root->glob->sublink_counter);
rte = addRangeTableEntryForSubquery(NULL, sub_select, makeAlias(subquery_name, NIL), false, false, true);
} else {
rte = addRangeTableEntryForSubquery(NULL, sub_select, makeAlias("subquery", NIL), false, false, true);
}
/* Append this query to rtable. */
parse->rtable = lappend(parse->rtable, rte);
/*
* Form a RangeTblRef for the pulled-up sub-select.
*/
rtr = makeNode(RangeTblRef);
rtr->rtindex = rtindex;
result = makeNode(JoinExpr);
result->jointype = JOIN_LEFT;
result->quals = test_quals;
result->larg = *jtlink1;
result->rarg = (Node*)rtr;
result->alias = NULL;
*jtlink1 = (Node*)result;
/* Mark query's can_push */
mark_parent_child_pushdown_flag(root->parse, sub_select);
}
return;
}
/*
* @Description: Convert sublink in op_expr to left join.
* @in root - Per-query information for planning/optimization.
* @in or_clause - current or clause.
* @in jtlink1 - current joinExpr
* @available_rels1 - available rel number.
* @replace - if the node should be replaced
* @isnull - isnull flag of clause
* @return - not null expr this expr will replace op_expr.
*/
Node*
convert_OREXPR_to_join(PlannerInfo *root, BoolExpr *or_clause,
Node *clause,
SubLink *expr_sublink,
Node **jtlink1,
Relids *available_rels,
bool replace,
bool isnull)
{
Query *subQuery = NULL;
List *EqualExprList = NULL;
Node *joinQual = NULL;
JoinExpr *result = NULL;
RangeTblEntry *rte = NULL;
RangeTblRef *rtr = NULL;
int rtindex = 0;
/* Judge this sublink if can pull up.*/
if (!safe_convert_ORCLAUSE(root, clause, expr_sublink, *available_rels)) {
return NULL;
}
subQuery = (Query *)copyObject(expr_sublink->subselect);
if (has_no_expand_hint(subQuery)) {
return NULL;
}
expr_sublink->subselect = (Node *)subQuery;
if (get_pullUp_equal_expr((Node*)subQuery->jointree, &EqualExprList) && EqualExprList) {
joinQual = transform_equal_expr(root, subQuery, EqualExprList, NULL, false, isnull);
/*
* Upper-level vars in subquery will now be one level closer to their
* parent than before; in particular, anything that had been level 1
* becomes level zero.
*/
IncrementVarSublevelsUp(joinQual, -1, 1);
/* Add new rtindex of rangeTblRef, append rindex to available rel number. */
rtindex = list_length(root->parse->rtable) + 1;
*available_rels = bms_add_member(*available_rels, rtindex);
/*
* Now, This sublink will be replaced by var which is come from new rtable,
* and this op_expr will as join quals.
*/
Node *decoratedConstraints = NULL;
Node *expr = (Node *) ((TargetEntry *)linitial(subQuery->targetList))->expr;
decoratedConstraints = generate_filter_on_opexpr_sublink(root, rtindex, (Node *) expr, subQuery);
if (decoratedConstraints != NULL) {
clause = replace_node_clause(clause,
(Node *)expr_sublink,
decoratedConstraints,
RNC_RECURSE_AGGREF);
}
/* Append subquery to rtable. */
rte = addRangeTableEntryForSubquery(NULL,
subQuery,
makeAlias("subquery", NIL),
false,
false,
true);
root->parse->rtable = lappend(root->parse->rtable, rte);
rtr = makeNode(RangeTblRef);
rtr->rtindex = rtindex;
result = makeNode(JoinExpr);
result->jointype = JOIN_LEFT;
result->quals = joinQual;
/*
* This op_expr already be pull up as current left join's join quals.
* So, we need delete this op_expr from the previous hoin expr.
*/
if (replace)
{
Assert(IsA(*jtlink1, JoinExpr));
JoinExpr *join_expr = (JoinExpr*)(*jtlink1);
join_expr->quals = replace_node_clause((Node *)join_expr->quals,
clause,
makeBoolConst(true, false),
RNC_RECURSE_AGGREF);
}
result->larg = *jtlink1;
result->rarg = (Node*)rtr;
result->alias = NULL;
/* Append JoinExpr to rtable. */
rte = addRangeTableEntryForJoin(NULL,
NIL,
result->jointype,
NIL,
result->alias,
true);
root->parse->rtable = lappend(root->parse->rtable, rte);
*jtlink1 = (Node*)result;
/* Mark query's can_push */
mark_parent_child_pushdown_flag(root->parse, subQuery);
list_free_ext(EqualExprList);
return clause;
}
else
{
ereport(DEBUG2, (errmodule(MOD_OPT_REWRITE),
(errmsg("[Sublink pull up failure reason]:"
" Sublink need 'equal' with suitable level vars and can only combined with 'and'."))));
list_free_ext(EqualExprList);
return NULL;
}
}
static void convert_to_join_by_sublinktype(PlannerInfo *root, BoolExpr *or_clause, Node **jtlink1,
Relids *available_rels1, bool isnull, SubLink *sublink)
{
switch (sublink->subLinkType) {
case EXISTS_SUBLINK:
convert_OREXISTS_to_join(root, or_clause, sublink, jtlink1, *available_rels1, isnull);
break;
case ANY_SUBLINK:
convert_ORANY_to_join(root, or_clause, sublink, jtlink1, *available_rels1);
break;
default:
break;
}
return;
}
/*
* @Description: Convert orclause's sublink to left join.
* @in root - Per-query information for planning/optimization.
* @in or_clause - current or clause.
* @in jtlink1 - current joinExpr
* @available_rels1 - available rel number.
*/
void convert_ORCLAUSE_to_join(PlannerInfo *root, BoolExpr *or_clause, Node **jtlink1, Relids *available_rels1)
{
List *sublinkList = NULL;
ListCell *lc = NULL;
List *pullExprList = pull_sublink((Node*)or_clause, PE_OPEXPR | PE_NULLTEST | PE_NOTCLAUSE, false);
Node *notNullExpr = NULL;
foreach(lc, pullExprList)
{
Node *clause = (Node *) lfirst(lc);
bool isnull = false;
SubLink *sublink = NULL;
switch(nodeTag(clause))
{
case T_NullTest:
if (((NullTest *) clause)->nulltesttype == IS_NULL)
isnull = true;
/* fall through */
case T_OpExpr:
{
bool replace = false;
ListCell *cell = NULL;
sublinkList = pull_sublink(clause, 0, false);
foreach(cell, sublinkList)
{
sublink = (SubLink*)lfirst(cell);
/* We only convert expr_sublink of or_clause to join. */
if (sublink->subLinkType != EXPR_SUBLINK) {
continue;
}
notNullExpr = convert_OREXPR_to_join(root, or_clause, clause, sublink,
jtlink1, available_rels1, replace, isnull);
if (notNullExpr != NULL) {
replace = true;
}
}
}
break;
case T_BoolExpr:
if (not_clause(clause)) {
/* If the immediate argument of NOT is EXISTS, try to convert */
sublink = (SubLink *) get_notclausearg((Expr *) clause);
/* not in sublink is not supported since it's not equality join */
if (!IsA(sublink, SubLink) ||
sublink->subLinkType == ANY_SUBLINK) {
continue;
}
/* keep isnull as false since not clause is always here */
} else {
continue;
}
/* fall through */
case T_SubLink:
if (IsA(clause, SubLink)) {
sublink = (SubLink *) clause;
}
root->glob->sublink_counter++;
convert_to_join_by_sublinktype(root, or_clause, jtlink1, available_rels1, isnull, sublink);
break;
default:
break;
}
}
return;
}
/*
* locate_base_var:
* Find if there's base table var in the input node, that
* has the same null property with input node
* Parameters:
* @in node: input node
* Output:
* return base table var if found, or NULL
*/
static Var* locate_base_var(Expr* node)
{
if (IsA(node, Var)) {
return (Var*)node;
}
while (IsA(node, RelabelType) || IsA(node, FuncExpr)) {
if (IsA(node, RelabelType)) {
node = ((RelabelType*)node)->arg;
} else if (IsA(node, FuncExpr)) {
FuncExpr* funcexpr = (FuncExpr*)node;
if (1 == list_length(funcexpr->args) && func_strict(funcexpr->funcid)) {
node = (Expr*)linitial(funcexpr->args);
} else {
break;
}
}
}
if (IsA(node, Var))
return (Var*)node;
return NULL;
}
/*
* CanExprHashable:
* Check whether pullup expr can hashable
* Parameters:
* @in node: list of expr pulled up
* Output:
* true for all expr pulled up can hashable
*/
static bool
CanExprHashable(List *pullUpEqualExpr)
{
ListCell *lc = NULL;
foreach(lc, pullUpEqualExpr) {
OpExpr *pullUpExpr = (OpExpr*)lfirst(lc);
ListCell *cell = NULL;
foreach(cell, pullUpExpr->args) {
Node *node = (Node*)lfirst(cell);
if (contain_vars_of_level(node, 0)) {
Oid sortop = InvalidOid;
Oid eqop = InvalidOid;
bool hashable = false;
get_sort_group_operators(exprType(node), false, true, false, &sortop, &eqop, NULL, &hashable);
if (!hashable)
return false;
}
}
}
return true;
}
/*
* push_down_one_query
*
* Adds a SELECT wrapper query that wraps around the original query.
* It works just like a query is being pushed down.
*
* root: the planner info of the query
* subquery: the planner info with the original query
*/
void push_down_one_query(PlannerInfo* root, Query** subquery)
{
Query* parse = root->parse;
RangeTblEntry* rte = NULL;
RangeTblRef* rtr = NULL;
List* targetlist = NIL;
ListCell* lc = NULL;
AttrNumber attnum = 1;
errno_t rc = EOK;
/* Wrapper only applies on SELECT query */
Assert(subquery != NULL);
AssertEreport(parse->commandType == CMD_SELECT, MOD_OPT_REWRITE,
"Cannot create SELECT wrapper on any queries other than a SELECT query.");
*subquery = makeNode(Query);
rc = memcpy_s((void*)(*subquery), sizeof(Query), parse, sizeof(Query));
securec_check_c(rc, "\0", "\0");
rc = memset_s((void*)parse, sizeof(Query), 0, sizeof(Query));
securec_check_c(rc, "\0", "\0");
/* Get simple subquery RTE */
rte = addRangeTableEntryForSubquery(NULL, *subquery, makeAlias("inner_subquery", NIL),
false, true);
/* Get range table reference */
rtr = makeNode(RangeTblRef);
rtr->rtindex = 1;
/* Get simple wrapper targetlist */
foreach(lc, (*subquery)->targetList) {
TargetEntry* tle = lfirst_node(TargetEntry, lc);
TargetEntry* tmp_tle = NULL;
Var* tmp_var = NULL;
char* attname = NULL;
if (tle->resjunk) {
continue;
}
if (tle->resname != NULL) {
attname = pstrdup(tle->resname);
}
tmp_var = makeVarFromTargetEntry((Index)1, tle);
tmp_tle = makeTargetEntry((Expr*)tmp_var, attnum, attname, false);
tmp_tle->resorigtbl = tle->resorigtbl;
tmp_tle->resorigcol = tle->resorigcol;
targetlist = lappend(targetlist, tmp_tle);
attnum++;
}
/* Create wrapper body, apply all components */
parse->type = T_Query;
parse->commandType = CMD_SELECT;
parse->targetList = targetlist;
parse->rtable = lappend(parse->rtable, rte);
parse->jointree = makeFromExpr(list_make1(rtr), NULL);
parse->can_push = (*subquery)->can_push;
parse->canSetTag = (*subquery)->canSetTag;
parse->hasSubLinks = (*subquery)->hasSubLinks;
/* The query string is remain unchanged, but it need to be copied */
if ((*subquery)->sql_statement != NULL) {
parse->sql_statement = pstrdup((*subquery)->sql_statement);
}
}
/*
* @brief pull_up_sort_limit_clause
* Pull up sort and limit clauses from subquery.
* @param query dest query
* @param subquery src query
* @param set_refs if true, reset sortgrouprefs, otherwise ignore
*/
void pull_up_sort_limit_clause(Query* query, Query* subquery, bool set_refs)
{
ListCell* lc = NULL;
List* sortreflist = NIL;
List* groupreflist = NIL;
query->sortClause = subquery->sortClause;
/* Pull up limit & offset */
query->limitCount = subquery->limitCount;
query->limitOffset = subquery->limitOffset;
/* Set Sort Group Refs on wrapper */
foreach(lc, subquery->sortClause) {
SortGroupClause* sgc = lfirst_node(SortGroupClause, lc);
TargetEntry* tle_in = NULL;
TargetEntry* tle = NULL;
tle_in = get_sortgroupclause_tle(sgc, subquery->targetList, set_refs);
if (tle_in == NULL) {
continue;
}
tle = get_tle_by_resno(query->targetList, tle_in->resno);
tle->ressortgroupref = tle_in->ressortgroupref;
sortreflist = lappend(sortreflist, tle_in);
}
if (set_refs) {
/* Unset Sort Group Refs on inner query */
foreach(lc, subquery->groupClause) {
SortGroupClause* sgc = lfirst_node(SortGroupClause, lc);
TargetEntry* tle = get_sortgroupclause_tle(sgc, subquery->targetList);
groupreflist = lappend(groupreflist, tle);
}
sortreflist = list_union(sortreflist, groupreflist);
sortreflist = list_difference(sortreflist, groupreflist);
foreach(lc, sortreflist) {
TargetEntry* tle = lfirst_node(TargetEntry, lc);
tle->ressortgroupref = 0;
}
}
/* Clear inner query clauses */
subquery->sortClause = NIL;
subquery->limitCount = NULL;
subquery->limitOffset = NULL;
/* Free temp lists */
list_free_ext(sortreflist);
list_free_ext(groupreflist);
}
/* Check if need to pull up non-correlated sublinks */
static bool safe_pullup_uncorrelated_sublink_where(Node* inout_quals, Query* subQuery, Relids* available_rels)
{
Relids level_up_varnos = NULL;
level_up_varnos = pull_varnos((Node*)subQuery->jointree, 1, true);
if (!bms_is_empty(level_up_varnos) && bms_is_subset(level_up_varnos, *available_rels)) {
bms_free(level_up_varnos);
return false;
}
bms_free(level_up_varnos);
if (!IsA(inout_quals, OpExpr)) {
return false;
}
return safe_pullup_op_expr_sublink((OpExpr*)inout_quals);
}
bool safe_pullup_op_expr_sublink(OpExpr* expr)
{
bool hasSublink = false;
Node* node = NULL;
ListCell *lc = NULL;
SubLink* sublink = NULL;
List* sublinkList = NULL;
foreach(lc, expr->args)
{
node = (Node*)lfirst(lc);
if (!IsA(node, SubLink)) {
continue;
}
hasSublink = true;
sublink = (SubLink*)node;
if (sublink->subLinkType != EXPR_SUBLINK) {
return false;
}
}
if (!hasSublink) {
return false;
}
// sublink should be only one
sublinkList = pull_sublink((Node*)expr, 0, false, false);
if (sublinkList == NULL || list_length(sublinkList) != 1) {
list_free_ext(sublinkList);
return false;
}
list_free_ext(sublinkList);
return true;
}
/*
* @brief safe_apply_winmagic
* Is it safe to use windows aggregation to eliminate the sublinks?
* For now, we need to keep the sublink as hassle-free as possible.
*
* @param root Planner info with original query
*/
bool safe_apply_winmagic(PlannerInfo* root, Node* sublink_qual, SubLink* sublink, Relids* available_rels)
{
Query* query = root->parse;
Query* subquery = castNode(Query, sublink->subselect);
List* aggreflist = NIL;
Relids level_up_varnos = NULL;
OpExpr* expr = NULL;
if (query->hasWindowFuncs ||
query->hasDistinctOn ||
subquery->hasWindowFuncs ||
subquery->hasDistinctOn) {
return false;
}
if (query->groupClause != NIL ||
query->groupingSets != NIL ||
subquery->groupClause != NIL ||
subquery->groupingSets != NIL ||
subquery->sortClause != NIL) {
return false;
}
if (subquery->limitOffset != NULL ||
subquery->limitCount != NULL) {
return false;
}
if (subquery->havingQual != NULL) {
return false;
}
/*
* Check if it is correlated.
*/
level_up_varnos = pull_varnos(subquery->jointree->quals, 1, true);
if (bms_is_empty(level_up_varnos) || !bms_is_subset(level_up_varnos, *available_rels)) {
return false;
}
/* Check num of correlation operations */
if (bms_num_members(level_up_varnos) > 1) {
return false;
}
if (list_length(query->rtable) != list_length(subquery->rtable) + 1) {
return false;
}
ListCell* lc = NULL;
ListCell* lc_sub = NULL;
Bitmapset* bms = NULL;
Bitmapset* bms_sub = NULL;
foreach(lc, query->rtable) {
RangeTblEntry* rte = (RangeTblEntry*)lfirst(lc);
if (rte->rtekind == RTE_RELATION &&
rte->alias == NULL &&
!bms_is_member(rte->relid, bms)) {
bms = bms_add_member(bms, rte->relid);
} else {
return false;
}
}
foreach(lc_sub, subquery->rtable) {
RangeTblEntry* rte_sub = (RangeTblEntry*)lfirst(lc_sub);
if (rte_sub->rtekind == RTE_RELATION &&
rte_sub->alias == NULL &&
!bms_is_member(rte_sub->relid, bms_sub)) {
bms_sub = bms_add_member(bms_sub, rte_sub->relid);
} else {
return false;
}
}
if (!bms_is_subset(bms_sub, bms) ||
!bms_nonempty_difference(bms, bms_sub) ||
bms_num_members(bms_difference(bms, bms_sub)) != 1) {
return false;
}
if (!quals_are_contained(subquery, query)) {
return false;
}
/* Check expr sublink */
if (!IsA(sublink_qual, OpExpr)) {
return false;
}
expr = (OpExpr*)(sublink_qual);
if (!safe_pullup_op_expr_sublink(expr)) {
return false;
}
/* Check number of aggs in subquery targetist */
aggreflist = pull_aggref((Node*)subquery->targetList);
if (list_length(aggreflist) != 1) {
list_free_ext(aggreflist);
return false;
}
list_free_ext(aggreflist);
return true;
}
static bool parent_contains(Query *query,
Oid left_rel,
AttrNumber left_attno,
Oid right_rel,
AttrNumber right_attno)
{
ListCell *lc = NULL;
List *list_quals = generate_quals_list(query->jointree->quals);
if (list_quals == NIL) {
return false;
}
foreach(lc, list_quals) {
OpExpr* op = (OpExpr*)lfirst(lc);
if (list_length(op->args) != WITH_TWO_ARGS) {
continue;
}
Node *left_node = (Node*)linitial(op->args);
Node *right_node = (Node*)lsecond(op->args);
if (IsA(left_node, RelabelType)) {
left_node = (Node*)(((RelabelType*)left_node)->arg);
}
if (IsA(right_node, RelabelType)) {
right_node = (Node*)(((RelabelType*)right_node)->arg);
}
if (!IsA(left_node, Var) || !IsA(right_node, Var)) {
continue;
}
if (!op_hashjoinable(op->opno, ((Var*)left_node)->vartype)) {
continue;
}
Var *var_first = (Var*)left_node;
Var *var_second = (Var*)right_node;
if (var_first->varlevelsup != 0 || var_second->varlevelsup != 0) {
continue;
}
RangeTblEntry *rte_first = rt_fetch(var_first->varno, query->rtable);
RangeTblEntry *rte_second = rt_fetch(var_second->varno, query->rtable);
if (rte_first->relid == rte_second->relid)
continue;
if (rte_first->relid == left_rel &&
var_first->varattno == left_attno) {
if (rte_second->relid == right_rel && var_second->varattno == right_attno) {
return true;
} else {
continue;
}
}
if (rte_first->relid == right_rel &&
var_first->varattno == right_attno) {
if (rte_second->relid == left_rel && var_second->varattno == left_attno) {
return true;
} else {
continue;
}
}
}
return false;
}
static bool parent_contains(Query *query,
Oid left_rel,
AttrNumber left_attno,
Const *op_const)
{
ListCell *lc = NULL;
Var *left_var = NULL;
Const *right_const = NULL;
List *list_quals = generate_quals_list(query->jointree->quals);
if (list_quals == NIL) {
return false;
}
foreach(lc, list_quals) {
OpExpr* op = (OpExpr*)lfirst(lc);
if (list_length(op->args) != WITH_TWO_ARGS) {
continue;
}
Node *left_node = (Node*)linitial(op->args);
Node *right_node = (Node*)lsecond(op->args);
if (IsA(left_node, RelabelType)) {
left_node = (Node*)(((RelabelType*)left_node)->arg);
}
if (IsA(right_node, RelabelType)) {
right_node = (Node*)(((RelabelType*)right_node)->arg);
}
if (IsA(left_node, Var) && IsA(right_node, Const)) {
left_var = (Var*)left_node;
right_const = (Const*)right_node;
} else if (IsA(right_node, Var) && IsA(left_node, Const)) {
left_var = (Var*)right_node;
right_const = (Const*)left_node;
} else {
continue;
}
if (!op_hashjoinable(op->opno, left_var->vartype)) {
continue;
}
if (left_var->varlevelsup != 0) {
continue;
}
RangeTblEntry *left_rte = rt_fetch(left_var->varno, query->rtable);
if (left_rte->relid == left_rel &&
left_var->varattno == left_attno &&
equal(right_const, op_const)) {
return true;
}
}
return false;
}
static bool quals_are_contained(Query* subquery, Query* query)
{
if (!IsA(subquery->jointree->quals, OpExpr) &&
!IsA(subquery->jointree->quals, BoolExpr)) {
return false;
}
Oid left_rel = InvalidOid;
Oid right_rel = InvalidOid;
AttrNumber left_attno = InvalidAttrNumber;
AttrNumber right_attno = InvalidAttrNumber;
ListCell* lc_op = NULL;
OpExpr* op_sub = NULL;
Var* left_var = NULL;
Var* right_var = NULL;
RangeTblEntry* rte_sub = NULL;
List* list_quals_sub = NIL;
bool corr = false;
list_quals_sub = generate_quals_list(subquery->jointree->quals);
if (list_quals_sub == NIL) {
return false;
}
foreach(lc_op, list_quals_sub) {
op_sub = (OpExpr*)(lfirst(lc_op));
if (list_length(op_sub->args) != WITH_TWO_ARGS) {
return false;
}
Node *left_node = (Node*)linitial(op_sub->args);
Node *right_node = (Node*)lsecond(op_sub->args);
if (IsA(left_node, RelabelType)) {
left_node = (Node*)(((RelabelType*)left_node)->arg);
}
if (IsA(right_node, RelabelType)) {
right_node = (Node*)(((RelabelType*)right_node)->arg);
}
if (IsA(left_node, Var) && IsA(right_node, Var)) {
if (!op_hashjoinable(op_sub->opno, ((Var*)left_node)->vartype)) {
return false;
}
left_var = (Var*)left_node;
if (left_var->varlevelsup == 1) {
/* only support one corr-condition */
if (corr) {
return false;
} else {
corr = true;
}
rte_sub = rt_fetch(left_var->varno, query->rtable);
} else {
rte_sub = rt_fetch(left_var->varno, subquery->rtable);
}
left_rel = rte_sub->relid;
left_attno = left_var->varattno;
right_var = (Var*)right_node;
if (right_var->varlevelsup == 1) {
/* only support one corr-condition */
if (corr) {
return false;
} else {
corr = true;
}
rte_sub = rt_fetch(right_var->varno, query->rtable);
} else {
rte_sub = rt_fetch(right_var->varno, subquery->rtable);
}
Assert (rte_sub->relid != InvalidOid);
right_rel = rte_sub->relid;
right_attno = right_var->varattno;
if (!parent_contains(query, left_rel, left_attno, right_rel, right_attno)) {
return false;
}
} else if (IsA(left_node, Var) && IsA(right_node, Const)) {
left_var = (Var*)left_node;
Const *right_const = (Const*)right_node;
if (left_var->varlevelsup != 0) {
return false;
}
rte_sub = rt_fetch(left_var->varno, subquery->rtable);
if (!parent_contains(query, rte_sub->relid, left_var->varattno, right_const)) {
return false;
}
} else if (IsA(left_node, Const) && IsA(right_node, Var)) {
right_var = (Var*)right_node;
Const *left_const = (Const*)left_node;
if (right_var->varlevelsup != 0) {
return false;
}
rte_sub = rt_fetch(right_var->varno, subquery->rtable);
if (!parent_contains(query, rte_sub->relid, right_var->varattno, left_const)) {
return false;
}
}
}
return true;
}
static List* generate_quals_list(Node* quals)
{
List* list_quals = NIL;
ListCell* lc = NULL;
if (IsA(quals, OpExpr)) {
list_quals = lappend(list_quals, quals);
} else {
BoolExpr* bool_sub = (BoolExpr*)(quals);
list_quals = pull_ands(bool_sub->args);
}
foreach(lc, list_quals) {
Node* and_arg = (Node*)lfirst(lc);
if (!IsA(and_arg, OpExpr)) {
return NIL;
}
}
return list_quals;
}
/*
* winmagic context initializer
*/
static void init_winmagic_context(WinmagicContext* wminfo)
{
wminfo->pullup_tlist = NIL;
wminfo->subquery_tlist = NIL;
wminfo->resno = 1;
wminfo->winresno = 1;
wminfo->outer_vars = NIL;
wminfo->inner_vars = NIL;
wminfo->winclause = NULL;
wminfo->orig_target_vars = NIL;
wminfo->orig_qual_vars = NIL;
wminfo->subtle = NULL;
/*
* pull vars lambda wrapper
* @param list list to append
* @param node get Vars from the node
*/
wminfo->pull_varlist = \
[](List* list, Node* node) -> List* {
return list_concat(list,
pull_var_clause(node,
PVC_RECURSE_AGGREGATES,
PVC_REJECT_PLACEHOLDERS,
PVC_RECURSE_SPECIAL_EXPR,
true, false));
};
/*
* replace nodes lamdba wrapper
* @param node the search space clause
* @param old old nodes to be replaced
* @param replace replacement nodes
*/
wminfo->replace_nodes = \
[](Node* node, Node* old, Node* replace) -> Node* {
return replace_node_clause(node, old, replace,
RNC_RECURSE_AGGREF);
};
}
/*
* Winmagic expr sublink sublink pullup
*
* Use windows aggregation to eliminate the sublinks.
* This method so-called winmagic can be more efficient is
* some cases than generic sublink pull up.
*
* But still, this is so far a very expensive optimization.
* Therefore, it is not always optimal especially for queries
* that is already fast enough.
*/
Node* convert_expr_sublink_with_winmagic(PlannerInfo* root, Node** jtlink1, Node* sublink_qual,
SubLink* sublink, Relids* available_rels)
{
Query* subquery = castNode(Query, sublink->subselect);
Query* query = NULL; /* new subquery */
TargetEntry* winreftle; /* targetlist entry referencing the winagg */
/* Winmagic context */
WinmagicContext wminfo;
init_winmagic_context(&wminfo);
/* Fill winmagic context values */
wminfo.orig_target_vars = \
wminfo.pull_varlist(NIL, (Node*)subquery->targetList);
wminfo.orig_qual_vars = \
wminfo.pull_varlist(NIL, subquery->jointree->quals);
wminfo.subtle = linitial_node(TargetEntry, subquery->targetList);
/* Expand original query targetlist */
winmagic_build_targetlist(root, sublink_qual, &wminfo);
/* Replace the entire operator with the filter with condition "true" */
root->parse->jointree->quals = \
wminfo.replace_nodes(root->parse->jointree->quals,
sublink_qual,
makeBoolConst(true, false));
/* Fix subquery vars */
winmagic_replace_varlist_varno(root->parse, subquery, &wminfo);
IncrementVarSublevelsUp((Node*)wminfo.orig_qual_vars, -1, 1);
/* Set targetlist */
root->parse->targetList = wminfo.subquery_tlist;
/* Change query structure */
push_down_one_query(root, &query);
/* Keep the sort and limit */
pull_up_sort_limit_clause(root->parse, query, false);
/* Set target list for the modified query */
root->parse->targetList = wminfo.pullup_tlist;
/* Set flags, might improve later */
query->hasWindowFuncs = true;
if (pull_aggref((Node*)root->parse->targetList) != NIL) {
root->parse->hasAggs = true;
}
query->hasAggs = false;
query->hasSubLinks = false;
/* Add sublink qual */
winreftle = get_tle_by_resno(query->targetList, wminfo.winresno);
sublink_qual = wminfo.replace_nodes((Node*)sublink_qual,
(Node*)wminfo.inner_vars,
(Node*)wminfo.outer_vars);
root->parse->jointree->quals = winmagic_get_sublink_qual(root, sublink, (Node*)wminfo.subtle->expr,
sublink_qual, winreftle);
/* Add winclause */
query->windowClause = list_make1(wminfo.winclause);
/* Redo parameter values hack */
bms_free_ext(*available_rels);
*available_rels = bms_make_singleton(1);
*jtlink1 = castNode(Node, root->parse->jointree);
return NULL;
}
/*
* Winmagic build targetlist for the original query
*
* For winmagic, the original query is converted into a
* subquery. Because the original targetlist need to take
* the result of window function as a input, original query's
* targetlist is pulled up to the new wrapper query. This
* function creates the new expanded targetlist to replace
* the original targetlist along with the new window func.
*/
static void winmagic_build_targetlist(PlannerInfo* root,
Node* sublink_qual,
WinmagicContext* wminfo)
{
ListCell* lc = NULL;
List* rtable = root->parse->rtable;
List* wintarget = NIL;
Aggref* aggref = NULL;
/*
* Collect original query's vars
* Those vars will be replaced by outer vars after
* their host being pulled up.
*/
wminfo->inner_vars = wminfo->pull_varlist(NIL, (Node*)root->parse->targetList);
wminfo->inner_vars = wminfo->pull_varlist(wminfo->inner_vars, sublink_qual);
/*
* Build outer vars & plain targetlist out of inner vars
*/
foreach(lc, wminfo->inner_vars) {
Var* var = lfirst_node(Var, lc);
Var* outer_var = NULL;
char* resname = NULL;
TargetEntry* tle = NULL;
RangeTblEntry* rte = rt_fetch(var->varno, rtable);
/* Get new target list */
resname = get_rte_attribute_name(rte, var->varattno);
tle = makeTargetEntry((Expr*)var, wminfo->resno, resname, false);
/* Get old target replacement Vars */
outer_var = makeVarFromTargetEntry((Index)1, tle);
wminfo->outer_vars = lappend(wminfo->outer_vars, outer_var);
wminfo->subquery_tlist = lappend(wminfo->subquery_tlist, tle);
wminfo->resno++;
}
/*
* Build & append window func target
*/
aggref = linitial_node(Aggref, pull_aggref((Node*)wminfo->subtle->expr));
wintarget = make_wintarget_with_aggref(aggref, wminfo);
wminfo->subquery_tlist = list_concat(wminfo->subquery_tlist, wintarget);
wminfo->resno++;
/* Update pull up target list with new vars */
wminfo->pullup_tlist = root->parse->targetList;
wminfo->pullup_tlist = (List*)wminfo->replace_nodes((Node*)wminfo->pullup_tlist,
(Node*)wminfo->inner_vars,
(Node*)wminfo->outer_vars);
}
/*
* make window func target entries & window clause
*
* Use the original aggref node along with the one
* levels up var to create window func and window
* clause.
*/
static List* make_wintarget_with_aggref(Aggref* aggref, WinmagicContext* wminfo)
{
WindowFunc* winfunc = NULL;
TargetEntry* wintle = NULL;
List* wintarget = NIL;
List* part_by_list = NULL;
List* varlist = NULL;
ListCell* lc = NULL;
/* Get vars from aggref */
varlist = wminfo->pull_varlist(varlist, (Node*)aggref);
/* Make window func & and the target entry */
winfunc = makeNode(WindowFunc);
winfunc->winfnoid = aggref->aggfnoid;
winfunc->wintype = aggref->aggtype;
winfunc->winref = 1; /* this is arbitrary, might improve later */
winfunc->winagg = true;
winfunc->args = varlist;
wintle = makeTargetEntry((Expr*)winfunc,
wminfo->resno,
pstrdup(wminfo->subtle->resname),
false);
wintarget = lappend(wintarget, wintle);
wminfo->winresno = wintle->resno;
wminfo->resno++;
/* Create list of ref targets */
foreach(lc, wminfo->orig_qual_vars) {
Var* var = lfirst_node(Var, lc);
TargetEntry* tle = NULL;
SortGroupClause* part_by = NULL;
Node* expr = castNode(Node, var);
Oid sortop = InvalidOid;
Oid eqop = InvalidOid;
bool hashable = false;
if (var->varlevelsup != 1) {
continue;
}
/* Make partition by clause */
get_sort_group_operators(exprType(expr),
true, true, false,
&sortop, &eqop,
NULL, &hashable);
part_by = makeNode(SortGroupClause);
part_by->tleSortGroupRef = wminfo->resno;
part_by->sortop = sortop;
part_by->eqop = eqop;
part_by->hashable = hashable;
part_by_list = lappend(part_by_list, part_by);
/* Make target entry */
tle = makeTargetEntry((Expr*)expr, wminfo->resno, NULL, true);
tle->ressortgroupref = wminfo->resno;
wintarget = lappend(wintarget, tle);
wminfo->resno++;
}
wminfo->winclause = makeNode(WindowClause);
wminfo->winclause->partitionClause = part_by_list;
wminfo->winclause->frameOptions = FRAMEOPTION_DEFAULTS;
wminfo->winclause->winref = winfunc->winref;
return wintarget;
}
/*
* Winmagic, get sublink qual
*
* Replace the entire sublink operation with proper filter.
* Returns the updated qual.
*/
static Node* winmagic_get_sublink_qual(PlannerInfo* root,
SubLink* sublink,
Node* sublink_expr,
Node* sublink_qual,
TargetEntry* winreftle)
{
Query* subquery = castNode(Query, sublink->subselect);
Node* sublink_filter = NULL;
List* winrefvars = NIL;
List* filtervars = NIL;
sublink_filter = generate_filter_on_opexpr_sublink(root,
(Index)1,
sublink_expr,
subquery);
filtervars = pull_var_clause(sublink_filter,
PVC_RECURSE_AGGREGATES,
PVC_REJECT_PLACEHOLDERS,
PVC_RECURSE_SPECIAL_EXPR);
winrefvars = list_make1(makeVarFromTargetEntry((Index)1, winreftle));
/* Replace sublink from sublink qual with proper filter */
if (sublink_filter != NULL) {
sublink_filter = replace_node_clause(sublink_filter,
(Node*)filtervars,
(Node*)winrefvars,
RNC_RECURSE_AGGREF | RNC_COPY_NON_LEAF_NODES);
sublink_qual = replace_node_clause(sublink_qual,
(Node*)sublink,
(Node*)sublink_filter,
RNC_RECURSE_AGGREF | RNC_COPY_NON_LEAF_NODES);
}
return sublink_qual;
}
/*
* Winmagic replace Vars' varno in subquery
*
* In winmagic, we try to combine the sublink and the upper query.
* Therefore, we replaced varno in src var list with pre-calculated
* varno map.
*/
static void winmagic_replace_varlist_varno(Query* dest_qry,
Query* src_qry,
WinmagicContext* wminfo)
{
ListCell* lc = NULL;
Index src_index = 0;
Index* varno_map = NULL;
int src_table_num = list_length(src_qry->rtable);
/* Allocate varno_map with len(rtable)+1 elements */
varno_map = (Index*)palloc0((src_table_num + 1) * sizeof(Index));
/* Fill varno_map */
foreach(lc, src_qry->rtable) {
RangeTblEntry* rte = lfirst_node(RangeTblEntry, lc);
ListCell* qlc = NULL;
Oid relid = InvalidOid;
Index dest_index = 0;
src_index++;
relid = rte->relid;
foreach(qlc, dest_qry->rtable) {
RangeTblEntry* qrte = lfirst_node(RangeTblEntry, qlc);
dest_index++;
if (qrte->relid == relid) {
varno_map[src_index] = dest_index;
break;
}
}
}
lc = NULL;
/* Create dest var list with mapped src vars */
foreach(lc, wminfo->orig_qual_vars) {
Var* src_var = lfirst_node(Var, lc);
if (src_var->varlevelsup > 0) {
continue;
}
src_var->varno = varno_map[src_var->varno];
}
foreach(lc, wminfo->orig_target_vars) {
Var* src_var = lfirst_node(Var, lc);
if (src_var->varlevelsup > 0) {
continue;
}
src_var->varno = varno_map[src_var->varno];
}
pfree_ext(varno_map);
}
Reference in New Issue View Git Blame Copy Permalink