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openGauss-server/src/gausskernel/optimizer/plan/planstartwith.cpp
Zongtian Hou d3a9de055f fix wrong answer in connectby nocycle & siblings case
2023-03-16 18:37:11 +08:00

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/*
* Copyright (c) 2020 Huawei Technologies Co.,Ltd.
* Portions Copyright (c) 2021, openGauss Contributors
*
* openGauss is licensed under Mulan PSL v2.
* You can use this software according to the terms and conditions of the Mulan PSL v2.
* You may obtain a copy of Mulan PSL v2 at:
*
* http://license.coscl.org.cn/MulanPSL2
*
* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
* See the Mulan PSL v2 for more details.
* ---------------------------------------------------------------------------------------
*
* planstartwith.cpp
* The query optimizer external interface.
*
* IDENTIFICATION
* src/gausskernel/optimizer/plan/planstartwith.cpp
*
* ---------------------------------------------------------------------------------------
*/
#include "postgres.h"
#include "knl/knl_variable.h"
#include <limits.h>
#include <math.h>
#include "access/transam.h"
#include "catalog/indexing.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_constraint.h"
#include "catalog/pgxc_group.h"
#include "catalog/pgxc_node.h"
#include "executor/executor.h"
#include "executor/node/nodeAgg.h"
#include "miscadmin.h"
#include "lib/bipartite_match.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "nodes/primnodes.h"
#ifdef OPTIMIZER_DEBUG
#include "nodes/print.h"
#endif
#include "optimizer/clauses.h"
#include "optimizer/cost.h"
#include "optimizer/nodegroups.h"
#include "optimizer/pathnode.h"
#include "optimizer/paths.h"
#include "optimizer/plancat.h"
#include "optimizer/planmain.h"
#include "optimizer/planner.h"
#include "optimizer/prep.h"
#include "optimizer/subselect.h"
#include "optimizer/tlist.h"
#include "parser/analyze.h"
#include "parser/parsetree.h"
#include "parser/parse_agg.h"
#include "rewrite/rewriteManip.h"
#include "securec.h"
#include "utils/rel.h"
#include "commands/prepare.h"
#include "pgxc/pgxc.h"
#include "optimizer/pgxcplan.h"
#include "optimizer/streamplan.h"
#include "workload/workload.h"
#include "optimizer/streamplan.h"
#include "utils/relcache.h"
#include "utils/selfuncs.h"
#include "utils/fmgroids.h"
#include "access/heapam.h"
#include "vecexecutor/vecfunc.h"
#include "executor/node/nodeRecursiveunion.h"
#include "executor/node/nodeCtescan.h"
#include "optimizer/randomplan.h"
#include "optimizer/optimizerdebug.h"
#include "parser/parse_oper.h"
#include "parser/parse_expr.h"
extern Node* preprocess_expression(PlannerInfo* root, Node* expr, int kind);
StartWithCTEPseudoReturnColumns g_StartWithCTEPseudoReturnColumns[] =
{
{"level", INT4OID, -1, InvalidOid},
{"connect_by_isleaf", INT4OID, -1, InvalidOid},
{"connect_by_iscycle", INT4OID, -1, InvalidOid},
{"rownum", INT4OID, -1, InvalidOid}
};
/*
* --------------------------------------------------------------------------------------
* Data & Local routines support major planning for start with
* --------------------------------------------------------------------------------------
*/
static StartWithOp *CreateStartWithOpNode(PlannerInfo *root,
CteScan *cteplan, RecursiveUnion *ruplan);
static void ProcessConnectByFakeConst(PlannerInfo *root, StartWithOp *swplan);
static void BuildStartWithInternalTargetList(PlannerInfo *root,
CteScan *cteplan, StartWithOp *swplan);
static void ProcessOrderSiblings(PlannerInfo *root, StartWithOp *swplan);
static void OptimizeStartWithPlan(PlannerInfo *root, StartWithOp *swplan);
#define SWCB_MATERIAL_OUTER_THREADHOLD 100
static inline bool NeedMaterialJoinOuter(Plan *outer, Plan *inner)
{
return (outer->total_cost > inner->total_cost * SWCB_MATERIAL_OUTER_THREADHOLD);
}
/*
* --------------------------------------------------------------------------------------
* Data & Local routines support internal Key/Col generation and also
* --------------------------------------------------------------------------------------
*/
typedef struct PullUpConnectByFuncVarContext {
PlannerInfo *root;
List *pullupVars;
CteScan *cteplan;
StartWithOp *swplan;
} PullUpConnectByFuncVarContext;
typedef struct PullUpConnectByFuncExprContext {
List *pullupFuncs;
} PullUpConnectByFuncExprContext;
static List *GetPRCTargetEntryList(PlannerInfo *root, RangeTblEntry *rte, StartWithOp *swplan);
static int GetVarPRCType(List *prcList, const Var* var);
static void MarkPRCNotSkip(StartWithOp *swplan, int prcType);
typedef struct ReplaceFakeConstContext {
Var *levelVar;
Var *rownumVar;
Node **nodeRef;
} ReplaceFakeConstContext;
static bool PullUpConnectByFuncVarsWalker(Node *node, PullUpConnectByFuncVarContext *context);
static List *PullUpConnectByFuncVars(PlannerInfo *root, CteScan *cteScan, Node *targetEntry);
static void CheckInvalidConnectByfuncArgs(CteScan *cteplan, Oid funcid, List *arg_vars);
static void GenerateStartWithInternalEntries(PlannerInfo *root, CteScan *cteplan,
List **keyEntryList, List **colEntryList);
static List* BuildStartWithPlanPseudoTargetList(Plan *plan, Index varno,
List *key_list, List *col_list, bool needSiblings);
static inline bool StartWithNeedSiblingSort(PlannerInfo *root, CteScan *cteplan)
{
Assert (IsA(cteplan, CteScan) && IsCteScanProcessForStartWith(cteplan));
return (cteplan->cteRef->swoptions->siblings_orderby_clause != NULL);
}
/*
* --------------------------------------------------------------------------------------
* Data & Local routines supporot ORDER SIBLING BY
* --------------------------------------------------------------------------------------
*/
#define SORTCMP_TOTAL_NUM 3
#define SORTCMP_LT 0
#define SORTCMP_EQ 1
#define SORTCMP_GT 2
#define CF_ONE 1
#define CF_TWO 2
#define TEXT_COLLCATION 100
typedef struct OrderSiblingSortEntry {
TargetEntry *tle;
bool sortCmpOp[SORTCMP_TOTAL_NUM];
bool sortByNullsFirst;
} OrderSiblingSortEntry;
static OrderSiblingSortEntry* CreateOrderSiblingSortEntry(
TargetEntry *entry, SortByDir dir);
static Sort *CreateSiblingsSortPlan(PlannerInfo* root, Plan* lefttree,
List *sortEntryList, double limit_tuples);
static Sort *CreateSortPlanUnderRU(PlannerInfo* root, Plan* lefttree,
List *siblings, double limit_tuples);
static char *CheckAndFixSiblingsColName(PlannerInfo *root, Plan *basePlan,
char *colname, TargetEntry *te);
static char *GetOrderSiblingsColName(PlannerInfo* root, SortBy *sb, Plan *basePlan);
/*
* --------------------------------------------------------------------------------------
* Data & Local routines supporot pseudo targetlist push down
* --------------------------------------------------------------------------------------
*/
#define UnknownVarno 0
#define MAX_PLAN_DEPTH 100
typedef struct StackNode {
Plan *value_array[MAX_PLAN_DEPTH];
int top;
} StackNode;
static inline void StackNodePush(StackNode *s, Plan *node)
{
s->top++;
s->value_array[s->top] = node;
}
static inline Plan* StackNodePop(StackNode *s)
{
if (s->top < 0) {
elog(ERROR, "error to pop() element in %s", __FUNCTION__);
}
Plan *node = s->value_array[s->top];
s->value_array[s->top] = NULL;
s->top--;
return node;
}
typedef struct StackVarno {
Index value_array[MAX_PLAN_DEPTH];
int top;
} StackVarno;
static inline void StackVarnoPush(StackVarno *s, Index varno)
{
s->top++;
s->value_array[s->top] = varno;
}
static inline Index StackVarnoPop(StackVarno *s)
{
if (s->top < 0) {
elog(ERROR, "error to pop() element in %s", __FUNCTION__);
}
Index varno = s->value_array[s->top];
s->value_array[s->top] = 0;
s->top--;
return varno;
}
typedef struct PlanAccessPathSearchContext {
Plan *topNode;
Plan *botNode;
List *fullEntryList;
StackNode planStack;
StackVarno varnoStack;
Index relid;
bool done;
int numsPrevTlist;
} PlanAccessPathSearchContext;
static void GetWorkTableScanPlanPath(PlannerInfo *root, Plan *node,
PlanAccessPathSearchContext *context);
static void BindPlanNodePseudoEntries(PlannerInfo *root, Plan *node, Index varno,
PlanAccessPathSearchContext *context);
static void AddPseudoEntries(Plan *plan, Index relid, PlanAccessPathSearchContext *context);
/*
* --------------------------------------------------------------------------------------
* EXPORT functions
* --------------------------------------------------------------------------------------
*/
/* -------------------------------------------------------------------------------------
* - brief: A helper function to determin if we need add pseudo *TLE* on CteScan node
* to fetch information to support start-with processing. Normally, if a CteScan
* node transfomed from Start/With with ORDER-SIBLINGS-BY, LEVEL, ISLEAF,
* ISCYCLE we need do so
* -------------------------------------------------------------------------------------
*/
bool IsCteScanProcessForStartWith(CteScan *ctescan)
{
if (!IsA((Plan *)ctescan, CteScan)) {
return false;
}
return (ctescan->cteRef != NULL && ctescan->cteRef->swoptions != NULL);
}
/*
* -------------------------------------------------------------------------------------
* - brief: A helper function to indicate if a target entry is for SWCB's internal
* target entry, e.g. RUTIR, array_key, array_col.
*
* - return: TRUE if tle->resname is RUITR/array_key/array_col
* -------------------------------------------------------------------------------------
*/
bool IsPseudoInternalTargetEntry(const TargetEntry *tle)
{
if (tle == NULL || tle->resname == NULL) {
return false;
}
StartWithOpColumnType type = GetPseudoColumnType(tle);
return (type == SWCOL_RUITR || type == SWCOL_ARRAY_KEY || type == SWCOL_ARRAY_COL || type == SWCOL_ARRAY_SIBLINGS);
}
/*
* -------------------------------------------------------------------------------------
* - brief: A helper function to indicate if a target entry is for SWCB's pseudo return
* columns
*
* - return: TRUE if tle->resname is level/rownum/iscycle/isleaf
* -------------------------------------------------------------------------------------
*/
bool IsPseudoReturnTargetEntry(const TargetEntry *tle)
{
if (tle == NULL || tle->resname == NULL) {
return false;
}
StartWithOpColumnType type = GetPseudoColumnType(tle);
return (type == SWCOL_LEVEL || type == SWCOL_ISLEAF ||
type == SWCOL_ISCYCLE || type == SWCOL_ROWNUM);
}
/*
* -------------------------------------------------------------------------------------
* - brief: function to help fix tlist with explicite name
*
* - return: return a new list with resname assigned
* -------------------------------------------------------------------------------------
*/
List *FixSwTargetlistResname(PlannerInfo *root, RangeTblEntry *curRte, List *tlist)
{
if (curRte->rtekind != RTE_CTE || !curRte->swConverted) {
elog(WARNING, "unusable case just original tlist");
return tlist;
}
int baseColNum = list_length(curRte->eref->colnames);
int natts = list_length(tlist);
if (natts - baseColNum != STARTWITH_PSEUDO_RETURN_ATTNUMS &&
baseColNum != natts) {
elog(ERROR, "unrecognized case baseColNum/tlist");
}
/* attach resname for target entry */
ListCell *lc = NULL;
List *newList = NIL;
AttrNumber attno = 0;
/* fix the origianl output column */
foreach (lc, tlist) {
TargetEntry *entry = (TargetEntry *)lfirst(lc);
const char *colname = NULL;
if (attno < baseColNum) {
colname = strVal(list_nth(curRte->eref->colnames, attno));
} else {
colname = g_StartWithCTEPseudoReturnColumns[attno - baseColNum].colname;
}
entry->resname = pstrdup(colname);
attno++;
newList = lappend(newList, entry);
}
return newList;
}
/*
* @Brief: identify if it is a connect by level/rownum plan node
*/
bool IsConnectByLevelStartWithPlan(const StartWithOp *plan)
{
Assert (IsA(plan, StartWithOp) && plan->swoptions != NULL);
return (plan->swoptions->connect_by_type == CONNECT_BY_LEVEL ||
plan->swoptions->connect_by_type == CONNECT_BY_ROWNUM ||
plan->swoptions->connect_by_type == CONNECT_BY_MIXED_LEVEL ||
plan->swoptions->connect_by_type == CONNECT_BY_MIXED_ROWNUM);
}
/*
* @Brief: return a INT const node value, 0 if not INT const, considered as exception
*/
int32 GetStartWithFakeConstValue(A_Const *n)
{
Assert (IsA(n, A_Const));
if (n->val.type == T_Integer) {
return n->val.val.ival;
} else {
elog(LOG, "Accept a other Const val when evaluate FakeConst to rownum/level");
return 0;
}
}
/*
* @Brief: return a INT const node value, 0 if not INT const, considered as exception
*/
int32 GetStartWithFakeConstValue(Const *val)
{
Assert (IsA(val, Const));
if (IsA(val, Const) && !((Const*)val)->constisnull &&
((Const*)val)->consttype == INT4OID) {
return DatumGetInt32(((Const*)val)->constvalue);
} else {
elog(LOG, "Accept an invalid Const val when evaluate FakeConst to rownum/level");
return 0;
}
}
static char* GetSiblingsColNameFromFunc(Node* node)
{
if (!IsA(node, FuncCall)) {
return NULL;
}
ListCell* lc = NULL;
foreach(lc, ((FuncCall*) node)->args) {
Node *n = (Node *) lfirst(lc);
if (!IsA(n, ColumnRef)) {
continue;
}
ColumnRef *cr = (ColumnRef *) n;
int len = list_length(cr->fields);
if (len == CF_ONE) {
return strVal(linitial(cr->fields));
} else if (len == CF_TWO) {
return strVal(lsecond(cr->fields));
}
}
return NULL;
}
/*
* @Brief: check fix order-siblings columns, normally we can find sort-key from from
* basePlan's targetlist, but some special case we need additional process:
* 1. check colname exists in base-plan's targetlist, return if ok
* 2. check colname exists in parse->targetlist's rename
* un-named expr, assign "?column?" as default
* 3. alias name
*
* For these cases, we need scan parse->targetlist(alias case) and find the basePlan's
* to recreate sort key
*/
static char *CheckAndFixSiblingsColName(PlannerInfo *root, Plan *basePlan,
char *colname, TargetEntry *te)
{
/* step1. check if searched colname exists in base-plan's targetlist */
char *resultColName = NULL;
ListCell *lc = NULL;
foreach (lc, basePlan->targetlist) {
TargetEntry *entry = (TargetEntry *)lfirst(lc);
if (entry->resname == NULL) {
continue;
}
char *label = strrchr(entry->resname, '@');
label += 1;
if (strcmp(colname, label) == 0) {
resultColName = colname;
break;
}
}
/*
* If resultColName is found in basePlan's targelist, it says we are in regular
* case and it is safely to build sort plan for Order-Sibling clause
*
* regular case, we found sort-entry in base-plan's targetlist
*/
if (resultColName != NULL) {
return resultColName;
}
/*
* step2. try to find sort-entry in parse->targetlist as resname(for alias case)
* case 1. regular alias, e.g. select id as alias_id,... te->resname: "alias_id"
* case 2. unnamed expr, e.g. select id * 2, pid,.... te->resname: "?column?"
*/
bool found = false;
if (te == NULL) {
/* normally for alias case */
foreach (lc, root->parse->targetList) {
te = (TargetEntry *)lfirst(lc);
/* te->resname may be null, so check it first */
if (te->resname && strcmp(te->resname, colname) == 0) {
found = true;
break;
}
}
/*
* Still not found just return origin colname, error-out later in sort-plan
* creation stage
*/
if (!found || te == NULL) {
return colname;
}
}
/* Pull the aggregates and var nodes from the quals */
List *vars = pull_var_clause((Node *)te->expr,
PVC_INCLUDE_AGGREGATES,
PVC_RECURSE_PLACEHOLDERS);
/*
* do not support none-table column's ref specified as order siblings's sort entry
*
* Keep origin behavior as previous version
*/
if (vars == NIL) {
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("expression with none-var in order siblings is not supported")));
}
/* do not support multi-column refs specified as order sibling's sort entry */
if (list_length(vars) > 1) {
ereport(WARNING, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("expression with multi-vars in order siblings is not full-supported,"
" only 1st var will be sorted.")));
}
Var *var = (Var *)linitial(vars);
RangeTblEntry *rte = root->simple_rte_array[var->varno];
char *raw_cte_alias = (char *)strVal(list_nth(rte->eref->colnames, var->varattno - 1));
resultColName = strrchr(raw_cte_alias, '@');
resultColName += 1; /* fix '@' offset */
return resultColName;
}
/*
* @Brief: Get Siblings column name according Siblings-SortBy Clause.
*/
static char *GetOrderSiblingsColName(PlannerInfo* root, SortBy *sb, Plan *basePlan)
{
char *colname = NULL;
TargetEntry *te = NULL;
if (IsA(sb->node, ColumnRef)) {
ColumnRef *cr = (ColumnRef *)sb->node;
int len = list_length(cr->fields);
if (len == CF_ONE) {
colname = strVal(linitial(cr->fields));
} else if (len == CF_TWO) {
colname = strVal(lsecond(cr->fields));
}
} else if (IsA(sb->node, A_Const)) {
A_Const *con = (A_Const *)sb->node;
Value* val = &((A_Const*)con)->val;
if (!IsA(val, Integer)) {
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("not integer constant in order siblings by clause")));
}
int siblingIdx = intVal(val);
if (siblingIdx > list_length(root->parse->targetList)) {
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("Order siblings by tlistIdx %d exceed length of targetList.", siblingIdx)));
}
te = (TargetEntry *)list_nth(root->parse->targetList, siblingIdx - 1);
if (IsA(te->expr, FuncExpr) && IsStartWithFunction((FuncExpr *)te->expr)) {
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("Not support refer startwithfunc column in order siblings by.")));
}
if (te->resname != NULL && IsPseudoReturnColumn(te->resname)) {
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("Not support refer startwith Pseudo column in order siblings by.")));
}
colname = te->resname;
}
/*
* We do not support function call as sort key here yet.
* Try to do our best by returning the first arg column anyway.
*/
if (colname == NULL) {
colname = GetSiblingsColNameFromFunc(sb->node);
}
/*
* Check and fix none regular columns, e.g. expr with no alias ?column? and
* name-alias that can not be found from StartWithOp plan's targetlist
*
* Special case: we do not have to process PRC
*/
if (colname != NULL && !IsPseudoReturnColumn(colname)) {
colname = CheckAndFixSiblingsColName(root, basePlan, colname, te);
}
return colname;
}
static Node* tryReplaceFakeConstWithTarget(Node* node, ReplaceFakeConstContext *context)
{
if (node == NULL) {
return node;
}
if (IsA(node, Const)) {
int constVal = GetStartWithFakeConstValue((Const *)node);
if (constVal == CONNECT_BY_LEVEL_FAKEVALUE) {
node = (Node*) context->levelVar;
} else if (constVal == CONNECT_BY_ROWNUM_FAKEVALUE) {
node = (Node *) context->rownumVar;
}
}
return node;
}
static bool ReplaceFakeConstWalker(Node *node, ReplaceFakeConstContext *context)
{
if (node == NULL) {
return false;
}
switch (node->type) {
case T_OpExpr: {
OpExpr *op = (OpExpr *)node;
List *newArgs = NIL;
ListCell *lc = NULL;
/* replace "fake-const" to level/rownum var attr */
foreach (lc, op->args) {
Node *n = (Node *)lfirst(lc);
n = tryReplaceFakeConstWithTarget(n, context);
newArgs = lappend(newArgs, n);
}
op->args= newArgs;
break;
}
case T_TypeCast: {
TypeCast* tc = (TypeCast*) node;
tc->arg = tryReplaceFakeConstWithTarget(tc->arg, context);
break;
}
case T_ScalarArrayOpExpr: {
ScalarArrayOpExpr* opexpr = (ScalarArrayOpExpr*)node;
ListCell *lc = NULL;
List *newArgs = NIL;
foreach (lc, opexpr->args) {
Node *n = (Node *)lfirst(lc);
n = tryReplaceFakeConstWithTarget(n, context);
newArgs = lappend(newArgs, n);
}
opexpr->args = newArgs;
break;
}
case T_FuncExpr: {
FuncExpr* fexpr = (FuncExpr*)node;
List *newArgs = NIL;
ListCell *lc = NULL;
/* replace "fake-const" to level/rownum var attr */
foreach (lc, fexpr->args) {
Node *n = (Node *)lfirst(lc);
n = tryReplaceFakeConstWithTarget(n, context);
newArgs = lappend(newArgs, n);
}
fexpr->args= newArgs;
break;
}
default: {
ereport(DEBUG1,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("StartWithOp's ConnectByLevel only suport simple connect-by expr"),
errdetail("Maybe you see the support scope of connect by level"),
errhint("Please check your connect by clause carefully")));
break;
}
}
return expression_tree_walker(node,
(bool (*)())ReplaceFakeConstWalker, (void*)context);
}
/*
* -------------------------------------------------------------------------------------
* @Brief: replace the fake-const value into real level/rownum attribute, so that we can
* do level/rownum condition check regularly
*
* Revisit the whole implementation for connect-by level/rownum:
* (1). In syntax stage, we convert level/rownum column into a "fake-const"
* (2). In semantic stage, as we don't add level/rownum pseodu return column to
* base table, so a "fake-const" value in connect-by expression ensure
* safe-transform
* (3). In planning state(StartWithOp), level/rownum pseudo column is inherited from
* CteScan, so we replace "fake-const" back to its correct format and do
* expression preprocess, SSQ/CSSQ can be proper planned into InitPlan/SubPlan
* -------------------------------------------------------------------------------------
*/
static void ReplaceFakeConst(PlannerInfo *root, StartWithOp *swplan)
{
StartWithOptions *swoptions = swplan->swoptions;
Node *connectByLevelExpr = swoptions->connect_by_level_quals;
/* Initialize replacement context */
errno_t rc = 0;
ReplaceFakeConstContext context;
rc = memset_s(&context,
sizeof(ReplaceFakeConstContext),
0,
sizeof(ReplaceFakeConstContext));
securec_check(rc, "\0", "\0");
/* Step 1. Find level/rownum pseudo return columns from startwith's targetlist */
ListCell *lc = NULL;
foreach (lc, swplan->plan.targetlist) {
TargetEntry *entry = (TargetEntry *)lfirst(lc);
if (pg_strcasecmp(entry->resname, "level") == 0) {
context.levelVar = (Var *)entry->expr;
}
if (pg_strcasecmp(entry->resname, "rownum") == 0) {
context.rownumVar = (Var *)entry->expr;
}
}
/* && rownumVar != NULL */
Assert (context.levelVar != NULL);
/* Step 2. Apply fake const replacement walker to the expression */
ReplaceFakeConstWalker(connectByLevelExpr, &context);
/* Step 3. Do reqular const expression process */
swoptions->connect_by_level_quals = eval_const_expressions(root, connectByLevelExpr);
}
/*
* - brief: Do possible post-path stage optimization, e.g. add Material node on an
* NestLoop's outer part
*
* - Note: Ideally should be handled in PathNode generation stage, in order to do so we have
* serveral case need to come up with e.g. identfy which SubQuery's output should be
* materilzed, for short term we only to improve to avoid the worst case where
* RuPlan's inner branch ReScan()-ed many times and its BaseRel with high selectivity
*/
static void OptimizeStartWithPlan(PlannerInfo *root, StartWithOp *swplan)
{
RecursiveUnion *ruplan = swplan->ruplan;
/* shunking only supported scenarios */
if (!IsA(innerPlan(ruplan), SubqueryScan)) {
return;
}
SubqueryScan *sqscan = (SubqueryScan *)innerPlan(ruplan);
Plan *joinPlan = sqscan->subplan;
/* only handle nestloop and hash join case */
if (!IsA(joinPlan, NestLoop) && !IsA(joinPlan, HashJoin)) {
return;
}
/* add materialize */
Plan *joinOuter = outerPlan(joinPlan);
Plan *joinInner = innerPlan(joinPlan);
Plan *wtscan = NULL;
/*
* Only handle WorkTableScan is in inner case, when WorkTableScan is in outer tree it
* can not be material-optimized as its result is volatile for each iteration.
*/
if (IsA(joinPlan, NestLoop) && IsA(joinInner, WorkTableScan)) {
wtscan = joinInner;
} else if (IsA(joinPlan, HashJoin) && IsA(joinInner, Hash) &&
IsA(joinInner->lefttree, WorkTableScan)) {
wtscan = joinInner->lefttree;
} else {
/* unrecognized cases */
return;
}
Assert (wtscan != NULL && IsA(wtscan, WorkTableScan));
if (!NeedMaterialJoinOuter(joinOuter, wtscan)) {
return;
}
Material *mtplan = make_material(joinOuter, true);
inherit_plan_locator_info((Plan *)mtplan, joinOuter);
copy_plan_costsize((Plan *)mtplan, joinOuter);
joinPlan->lefttree = (Plan *)mtplan;
}
/*
* -------------------------------------------------------------------------------------
* @Brief: The major processing logic entry point for start-with, given a CteScan node,
* we insert a StartWithOp proc node to do START WITH .... CONNECT BY processing,
* normally the process is separate many steps, see details as below:
*
* step(1): Create StartWithOp node and insert it between CtScan and RuScan, also replace
* the subplan refs in current PlannerInfo level
* step(2): Process ConnectByLevel/Rownum's fake const value
* step(3): Add possible post-path generation plan optimization e.g. rescan-avoid for
* start with
* step(4): Create Internal target list (RUITR/array_key/array_columns)
* step(5): Specially process ORDER SIBLINGS BY case
* -------------------------------------------------------------------------------------
*/
Plan *AddStartWithOpProcNode(PlannerInfo *root, CteScan *cteplan, RecursiveUnion *ruplan)
{
Plan *plan = (Plan *)cteplan;
StartWithOp *swplan = NULL;
/*
* Step1. Create a StartWithOp node between CteScan and RuScan, also update
* SubPlan-ref in curernt PlannerInfo's glob->subplans
*/
swplan = CreateStartWithOpNode(root, cteplan, ruplan);
/*
* Step2. In case of connect by level/rownum, we need create new quals to evaluate
* level/rownum condition in StartWith operator
*/
ProcessConnectByFakeConst(root, swplan);
/*
* Step3. Do some possible post-path generation plan optimization, to avoid worst
* cases, e.g. recursive part with high selectivity but rescan many times
*/
OptimizeStartWithPlan(root, swplan);
/*
* Step4. Add internal TargetEntryList to CteScan & RuScan, also add some runtime level
* optimization hints, e.g. swSkipOptions
*/
BuildStartWithInternalTargetList(root, cteplan, swplan);
/*
* Step5. Process order-siblings cases
*/
ProcessOrderSiblings(root, swplan);
/* Copy Params from ruplan */
swplan->plan.extParam = bms_copy(ruplan->plan.extParam);
swplan->plan.allParam = bms_copy(ruplan->plan.allParam);
return plan;
}
/*
* Local Routines to support AddStartWithOpProcNode()
*/
static StartWithOp* CreateStartWithOpNode(PlannerInfo *root,
CteScan *cteplan, RecursiveUnion *ruplan)
{
Plan *plan = (Plan *)cteplan;
StartWithOp *swplan = NULL;
Index relid = cteplan->scan.scanrelid;
int natts = 0;
RangeTblEntry *rte = NULL;
/* 1. fix targetlist with explict name */
natts = list_length(plan->targetlist);
rte = rt_fetch(relid, root->parse->rtable);
plan->targetlist = FixSwTargetlistResname(root, rte, plan->targetlist);
/* 2. Build StartWithOp's targetlist */
swplan = makeNode(StartWithOp);
swplan->plan.lefttree = (Plan *)ruplan;
swplan->plan.targetlist = (List *)copyObject(plan->targetlist);
swplan->ruplan = ruplan;
swplan->cteplan = cteplan;
swplan->swoptions = (StartWithOptions *)copyObject(cteplan->cteRef->swoptions);
/* generate PRC list for both swplan and ctescan */
swplan->prcTargetEntryList = GetPRCTargetEntryList(root, rte, swplan);
cteplan->prcTargetEntryList = (List *)copyObject(swplan->prcTargetEntryList);
/* Inherit ctescan's targetlist to StartWithOp */
inherit_plan_locator_info((Plan *)swplan, plan);
copy_plan_costsize((Plan *)swplan, (Plan *)ruplan);
/*
* Initialize PRC runtime optimization hints.
*
* Basically, we do optimistic scheme assuming all PRC on CTE is able to skip
*/
{
SetColumnSkipOptions(swplan->swExecOptions);
/* Mark level/rownum is not skipped, as they are lit-enough */
ClearSkipLevel(swplan->swExecOptions);
SetSkipIsLeaf(swplan->swExecOptions);
SetSkipIsCycle(swplan->swExecOptions);
ClearSkipRownum(swplan->swExecOptions);
}
/* fix original Ruplan refered place */
cteplan->subplan = (RecursiveUnion *)swplan;
List *newSubplans = NIL;
ListCell *lc = NULL;
foreach (lc, root->glob->subplans) {
Plan *plan = (Plan *)lfirst(lc);
if (IsA(plan, RecursiveUnion) && (Plan *)plan == (Plan *)ruplan) {
plan = (Plan *)swplan;
}
newSubplans = lappend(newSubplans, plan);
}
root->glob->subplans = newSubplans;
return swplan;
}
static void ProcessConnectByFakeConst(PlannerInfo *root, StartWithOp *swplan)
{
if (!IsConnectByLevelStartWithPlan(swplan)) {
return;
}
StartWithOptions *swoptions = swplan->swoptions;
/* fix fake const in qual expr */
ReplaceFakeConst(root, swplan);
/* do preprocess for connect-by-level/rownum condition */
((Plan *)swplan)->qual = (List *)preprocess_expression(root,
swoptions->connect_by_level_quals, EXPRKIND_QUAL);
}
static void BuildStartWithInternalTargetList(PlannerInfo *root,
CteScan *cteplan, StartWithOp *swplan)
{
List *keyEntryList = NIL;
List *colEntryList = NIL;
bool needSiblings = (swplan->swoptions->siblings_orderby_clause != NULL) ? true : false;
/* Generate internal target entry keyEntryList & colEntryList */
GenerateStartWithInternalEntries(root, cteplan, &keyEntryList, &colEntryList);
if (keyEntryList == NULL) {
ereport(DEBUG1,
(errmodule(MOD_OPT_PLANNER), errmsg("keyEntryList is NULL, query:%s",
t_thrd.postgres_cxt.debug_query_string)));
}
if (colEntryList == NULL) {
ereport(DEBUG1,
(errmodule(MOD_OPT_PLANNER), errmsg("colEntryList is NULL, query:%s",
t_thrd.postgres_cxt.debug_query_string)));
}
/* Add internal key/col entry list and pseudo_list for StartWithOp node */
swplan->internalEntryList =
BuildStartWithPlanPseudoTargetList((Plan *)swplan, cteplan->scan.scanrelid,
keyEntryList,
colEntryList,
needSiblings);
/* Add internal key/col entry list for CteScan node */
cteplan->internalEntryList =
BuildStartWithPlanPseudoTargetList((Plan *)cteplan, cteplan->scan.scanrelid,
keyEntryList,
colEntryList,
needSiblings);
/* construct fullEntryList (RUITR + array_key + array_col ) */
List *fullEntryList = NIL;
ListCell *entry = NULL;
foreach (entry, cteplan->scan.plan.targetlist) {
TargetEntry *te = (TargetEntry *)lfirst(entry);
/* skip regular columns */
if (IsPseudoReturnTargetEntry(te) || IsPseudoInternalTargetEntry(te)) {
fullEntryList = lappend(fullEntryList, copyObject(te));
}
}
swplan->keyEntryList = keyEntryList;
swplan->colEntryList = colEntryList;
swplan->fullEntryList = fullEntryList;
}
static void ProcessOrderSiblings(PlannerInfo *root, StartWithOp *swplan)
{
CteScan *cteplan = swplan->cteplan;
RecursiveUnion *ruplan = swplan->ruplan;
StartWithOptions *swoptions = swplan->swoptions;
if (!StartWithNeedSiblingSort(root, cteplan)) {
return;
}
/* Fix RecursiveUnion TargetList */
ListCell *lc = NULL;
foreach(lc, cteplan->scan.plan.targetlist) {
TargetEntry *te = (TargetEntry *)lfirst(lc);
if (IsPseudoReturnColumn(te->resname)) {
ruplan->plan.targetlist = lappend(ruplan->plan.targetlist, te);
}
}
ruplan->internalEntryList =
BuildStartWithPlanPseudoTargetList((Plan *)ruplan, cteplan->scan.scanrelid,
swplan->keyEntryList,
swplan->colEntryList,
true);
/* 1. Add under RU sort plan */
ruplan->plan.lefttree = (Plan *)CreateSortPlanUnderRU(root, ruplan->plan.lefttree,
swoptions->siblings_orderby_clause, -1);
ruplan->plan.righttree = (Plan *)CreateSortPlanUnderRU(root, ruplan->plan.righttree,
swoptions->siblings_orderby_clause, -1);
}
/*
* --------------------------------------------------------------------------------------
* LOCAL functions
* --------------------------------------------------------------------------------------
*/
/*
* @Brief: build full pseudo entries for given pro node, with input a keylist and collist
*
* pseudo target list
* [1]. RUIRT
* [2]. array_key_1
* [3]. array_col_2
* [4]. array_col_3
* [6]....
*
* example:
* Table:
* t1(id, name, fatherid, name_desc)
* Query:
* select *,
* level, connect_by_isleaf, connect_is_cycle,
* connect_by_root name_desc, sys_connect_by_path(name, '@')
* from t1
* start with name = 'shanghai'
* connect by id = PRIOR fatherid;
*
* pseudo-targetlist: array [
* - RUTI(type:int)
* - array_key_1(type:text)
* - array_col_2(type:text)
* - array_col_4(type:text)
* ]
*/
static List* BuildStartWithPlanPseudoTargetList(Plan *plan, Index varno,
List *key_list, List *col_list, bool needSiblings)
{
Node *expr = NULL;
TargetEntry *te = NULL;
TargetEntry *pte = NULL;
List *internalEntryList = NIL;
int rc = 0;
/* we only have to handle CteScan & RecursiveUnion node */
Assert (IsA(plan, CteScan) || IsA(plan, RecursiveUnion) || IsA(plan, StartWithOp));
/* 1. Add "RUITR" entry to support LEVEL */
expr = (Node *)makeVar(varno, list_length(plan->targetlist) + 1,
INT4OID, -1, InvalidOid, 0);
pte = makeTargetEntry((Expr *)expr, list_length(plan->targetlist) + 1, "RUITR", false);
plan->targetlist = lappend(plan->targetlist, pte);
internalEntryList = lappend(internalEntryList, pte);
/*
* 2. Add "array_key" entry we have to add to support connect_by_isleaf, connect_by_iscycle,
* order-siblings
*/
ListCell *lc = NULL;
foreach (lc, key_list) {
te = (TargetEntry *)lfirst(lc);
char resname[NAMEDATALEN] = {0};
rc = sprintf_s(resname, NAMEDATALEN, "array_key_%d", te->resno);
securec_check_ss(rc, "\0", "\0");
expr = (Node *)makeVar(varno, list_length(plan->targetlist) + 1,
TEXTOID, -1, TEXT_COLLCATION, 0);
pte = makeTargetEntry((Expr *)expr, list_length(plan->targetlist) + 1,
pstrdup(resname), false);
plan->targetlist = lappend(plan->targetlist, pte);
internalEntryList = lappend(internalEntryList, pte);
}
/*
* 3. Add "array_col" to support , connect_by_root
*/
foreach (lc, col_list) {
te = (TargetEntry *)lfirst(lc);
char resname[NAMEDATALEN] = {0};
rc = sprintf_s(resname, NAMEDATALEN, "array_col_%d", te->resno);
securec_check_ss(rc, "\0", "\0");
expr = (Node *)makeVar(varno, list_length(plan->targetlist) + 1,
TEXTOID, -1, TEXT_COLLCATION, 0);
pte = makeTargetEntry((Expr *)expr, list_length(plan->targetlist) + 1,
pstrdup(resname), false);
plan->targetlist = lappend(plan->targetlist, pte);
internalEntryList = lappend(internalEntryList, pte);
}
/*
* Add "array_siblings" pseudo columns support if need
*/
if (needSiblings) {
expr = (Node *)makeVar(varno, list_length(plan->targetlist) + 1,
BYTEAOID, -1, 0, 0);
pte = makeTargetEntry((Expr *)expr, list_length(plan->targetlist) + 1, "array_siblings", false);
plan->targetlist = lappend(plan->targetlist, pte);
internalEntryList = lappend(internalEntryList, pte);
}
return internalEntryList;
}
/*
* @brief: check if a given connect by function is valid for its args, currently only
* connect_by_root()/sys_connect_by_path() is supported
*/
static void CheckInvalidConnectByfuncArgs(CteScan *cteplan, Oid funcid, List *arg_vars)
{
/* for none connect by function we do not do arg checks on its type */
if (funcid != CONNECT_BY_ROOT_FUNCOID && funcid != SYS_CONNECT_BY_PATH_FUNCOID) {
return;
}
int maxBaseRelAttnum =
list_length(cteplan->scan.plan.targetlist) - STARTWITH_PSEUDO_RETURN_ATTNUMS;
/* validate common cases */
if (list_length(arg_vars) > 1) {
elog(ERROR, "only single column can be put as argument in connect_by_root/sys_connect_by_path()");
}
/*
* For compatible with Oracle where sys_connect_by_path() and connect_by_root()
* allow a const value set as 1st paramameter, return anyway
*/
if (arg_vars == NIL) {
return;
}
Var *arg = (Var *)linitial(arg_vars);
if (arg->varattno > maxBaseRelAttnum) {
elog(ERROR, "only base table column can be specified in connect_by_root/sys_connect_by_path()");
}
/* valid specific cases */
switch (funcid) {
case CONNECT_BY_ROOT_FUNCOID: {
/* for connect_by_root() we only check if base column */
break;
}
case SYS_CONNECT_BY_PATH_FUNCOID: {
/* for sys_connect_by_path() allow textual data types TEXT/VARCHAR/CHAR */
Oid typid = arg->vartype;
if (typid != TEXTOID && typid != VARCHAROID && typid != BPCHAROID &&
typid != NVARCHAR2OID) {
elog(ERROR, "only text type(CHAR/VARCHAR/NVARCHAR2/TEXT) is allow for sys_connect_by_path()");
}
break;
}
default: {
elog(ERROR, "unknown functions funid:%u in ConnectByFuncArg check.", funcid);
}
}
}
static bool PullUpConnectByFuncExprWalker(Node *node, PullUpConnectByFuncExprContext *context)
{
if (node == NULL) {
return false;
}
/* FuncExpr we do connect-by func validation check */
if (IsA(node, FuncExpr)) {
FuncExpr *func = (FuncExpr *)node;
/* Only handle start with hierachocal query's function cases */
if (IsHierarchicalQueryFuncOid(func->funcid)) {
context->pullupFuncs = list_append_unique(context->pullupFuncs, func);
}
}
return expression_tree_walker(node, (bool (*)())PullUpConnectByFuncExprWalker, (void *)context);
}
List *pullUpConnectByFuncExprs(Node* node)
{
errno_t rc = 0;
PullUpConnectByFuncExprContext context;
rc = memset_s(&context,
sizeof(PullUpConnectByFuncExprContext),
0,
sizeof(PullUpConnectByFuncExprContext));
securec_check(rc, "\0", "\0");
(void)PullUpConnectByFuncExprWalker(node, &context);
return context.pullupFuncs;
}
/*
* --------------------------------------------------------------------------------------
* @Brief: Functions to support var pull up from subquery's target list, also check each
* possible vars, so that we can do possible PRC skip optimizations
*
* PullUpConnectByFuncVars()
* --------------------------------------------------------------------------------------
*/
static List *PullUpConnectByFuncVars(PlannerInfo *root, CteScan *cteScan, Node *targetEntry)
{
errno_t rc = 0;
PullUpConnectByFuncVarContext context;
rc = memset_s(&context,
sizeof(PullUpConnectByFuncVarContext),
0,
sizeof(PullUpConnectByFuncVarContext));
securec_check(rc, "\0", "\0");
context.root = root;
context.pullupVars = NIL;
context.cteplan = cteScan;
context.swplan = (StartWithOp *)cteScan->subplan;
(void)PullUpConnectByFuncVarsWalker(targetEntry, &context);
return context.pullupVars;
}
static bool PullUpConnectByFuncVarsWalker(Node *node, PullUpConnectByFuncVarContext *context)
{
if (node == NULL) {
return false;
}
/*
* We handle two cases here:
* 1. FuncExpr we do connect-by func validation check
* 2. Var, we check if its PRC and possible PRC-skip optimization could apply
*/
if (IsA(node, FuncExpr)) {
FuncExpr *func = (FuncExpr *)node;
/* Only handle start with hierachocal query's function cases */
if (IsHierarchicalQueryFuncOid(func->funcid)) {
/* pull-up basic vars from FuncExpr node */
List *vars = pull_var_clause((Node*)func->args,
PVC_RECURSE_AGGREGATES, PVC_INCLUDE_PLACEHOLDERS);
CheckInvalidConnectByfuncArgs(context->cteplan, func->funcid, vars);
context->pullupVars = list_concat_unique(context->pullupVars, vars);
}
} else if (IsA(node, Var)) {
/* check if there is target var refer to PRC and mark them not-skipable */
Var *var = (Var *)node;
int prcType = GetVarPRCType(context->cteplan->prcTargetEntryList, var);
if (prcType == SWCOL_LEVEL || prcType == SWCOL_ISLEAF ||
prcType == SWCOL_ISCYCLE || prcType == SWCOL_ROWNUM) {
MarkPRCNotSkip(context->swplan, prcType);
}
}
return expression_tree_walker(node,
(bool (*)())PullUpConnectByFuncVarsWalker, (void*)context);
}
/*
* --------------------------------------------------------------------------------------
* @Brief: Functions to relevant to PRC optimization in hierachical queries
* - GetPRCTargetEntryList()
* - GetVarPRCType()
* - MarkPRCNotSkip()
* --------------------------------------------------------------------------------------
*/
static List *GetPRCTargetEntryList(PlannerInfo *root, RangeTblEntry *rte, StartWithOp *swplan)
{
int natts = 0;
int baseColNum = 0;
Plan *plan = (Plan *)swplan;
List *prcTargetEntryList = NIL;
/* check if PRC targetlist is already generated */
if (swplan->prcTargetEntryList != NIL) {
return swplan->prcTargetEntryList;
}
baseColNum = list_length(rte->eref->colnames) - STARTWITH_PSEUDO_RETURN_ATTNUMS;
natts = list_length(plan->targetlist);
if (natts - baseColNum != STARTWITH_PSEUDO_RETURN_ATTNUMS &&
baseColNum != natts) {
elog(ERROR, "unrecognized case baseColNum/tlist");
}
/* attach resname for target entry */
ListCell *lc = NULL;
foreach (lc, plan->targetlist) {
TargetEntry *entry = (TargetEntry *)lfirst(lc);
if (entry->resno > baseColNum) {
prcTargetEntryList = lappend(prcTargetEntryList, entry);
}
}
Assert (prcTargetEntryList != NIL);
return prcTargetEntryList;
}
static int GetVarPRCType(List *prcList, const Var* var)
{
ListCell *lc = NULL;
int prcType = SWCOL_LEVEL;
foreach (lc, prcList) {
TargetEntry *tle = (TargetEntry *)lfirst(lc);
if (!equal(var, tle->expr)) {
prcType++;
continue;
}
break;
}
/* none-prc column, we consider its type as unknown */
if (prcType != SWCOL_LEVEL && prcType != SWCOL_ISLEAF &&
prcType != SWCOL_ISCYCLE && prcType != SWCOL_ROWNUM) {
prcType = SWCOL_UNKNOWN;
}
return prcType;
}
static void MarkPRCNotSkip(StartWithOp *swplan, int prcType)
{
if (prcType == SWCOL_LEVEL || prcType == SWCOL_ROWNUM) {
return;
}
switch (prcType) {
case SWCOL_ISLEAF: {
ClearSkipIsLeaf(swplan->swExecOptions);
break;
}
case SWCOL_ISCYCLE: {
ClearSkipIsCycle(swplan->swExecOptions);
break;
}
default: {
/* do nothing */
}
}
return;
}
/*
* --------------------------------------------------------------------------------------
* @Brief: Generate internal entries for given CteScan node, here the term internal
* entry of key-value arraies prfixed with "array_key_nn" & col-value arraies
* prefixed with "array_col_mm" and store them in separate output list parm
*
* @param:
* - cteplan: the target CtePlan node where we generate key/col array
* - keyEntryList: A ** pointer to accept pseudo key entry
* - colEntryList: A ** pointer to accept pseudo col entry
*
* @Return: void, return value are set in keyEntryList & colEntryList
* --------------------------------------------------------------------------------------
*/
static void GenerateStartWithInternalEntries(PlannerInfo *root, CteScan *cteplan,
List **keyEntryList, List **colEntryList)
{
Assert (IsA(cteplan, CteScan) && IsA(cteplan->subplan, StartWithOp));
Plan *plan = (Plan *)cteplan;
StartWithOp *swplan = (StartWithOp *)cteplan->subplan;
ListCell *lc = NULL;
List *tmp_list = NULL;
/*
* First, match cte targetEntry in funcs like connect_by_root(xxx) and
* SYS_CONNECT_BY_PATH(xxx, '/')
*/
foreach(lc, root->parse->targetList) {
TargetEntry *tle = (TargetEntry *)lfirst(lc);
List *vars = PullUpConnectByFuncVars(root, cteplan, (Node *)tle);
tmp_list = list_concat(tmp_list, vars);
}
/* process those specified in where clause */
foreach(lc, plan->qual) {
TargetEntry *origin = (TargetEntry *)lfirst(lc);
List *vars = PullUpConnectByFuncVars(root, cteplan, (Node *)origin);
tmp_list = list_concat(tmp_list, vars);
}
foreach (lc, plan->targetlist) {
TargetEntry *te = (TargetEntry *)lfirst(lc);
Assert (IsA(te->expr, Var));
if (list_member(tmp_list, te->expr)) {
*colEntryList = lappend(*colEntryList, te);
}
}
/*
* Second, match cte targetEntry of connectby prior columns, like prior pid = id then pid is
* key
*/
CommonTableExpr *cteRef = cteplan->cteRef;
foreach(lc, cteRef->swoptions->prior_key_index) {
int index = lfirst_int(lc);
TargetEntry *te = (TargetEntry *)list_nth(plan->targetlist, index);
*keyEntryList = lappend(*keyEntryList, te);
}
/* do not skip iscycle PRC if "nocycle" is specified in HQ clause */
if (swplan->swoptions->nocycle) {
ClearSkipIsCycle(swplan->swExecOptions);
}
return;
}
/*
* @Brief: Add sort operator on top of CteScan with column with sort key
* {"LEVEL", "sibling_order_columns"}
*/
static OrderSiblingSortEntry* CreateOrderSiblingSortEntry(TargetEntry *entry, SortByDir dir)
{
OrderSiblingSortEntry *sortEntry =
(OrderSiblingSortEntry *)palloc0(sizeof(OrderSiblingSortEntry));
sortEntry->tle = entry;
switch (dir) {
case SORTBY_DEFAULT:
case SORTBY_ASC: {
sortEntry->sortCmpOp[SORTCMP_LT] = true;
sortEntry->sortCmpOp[SORTCMP_EQ] = true;
sortEntry->sortCmpOp[SORTCMP_GT] = false;
break;
}
case SORTBY_DESC: {
sortEntry->sortCmpOp[SORTCMP_LT] = false;
sortEntry->sortCmpOp[SORTCMP_EQ] = false;
sortEntry->sortCmpOp[SORTCMP_GT] = true;
break;
}
default: {
/* for default case we treat as ASC */
sortEntry->sortCmpOp[SORTCMP_LT] = true;
sortEntry->sortCmpOp[SORTCMP_EQ] = false;
sortEntry->sortCmpOp[SORTCMP_GT] = false;
}
}
return sortEntry;
}
static Sort *CreateSiblingsSortPlan(PlannerInfo* root, Plan* lefttree,
List *sortEntryList, double limit_tuples)
{
Sort *sort = NULL;
int numsortkeys = list_length(sortEntryList);
AttrNumber* sortColIdx = (AttrNumber*)palloc(numsortkeys * sizeof(AttrNumber));
Oid* sortOperators = (Oid*)palloc(numsortkeys * sizeof(Oid));
Oid* collations = (Oid*)palloc(numsortkeys * sizeof(Oid));
bool* nullsFirst = (bool*)palloc(numsortkeys * sizeof(bool));
numsortkeys = 0;
Oid sortoplt = InvalidOid;
Oid sortopeq = InvalidOid;
Oid sortopgt = InvalidOid;
bool hashable = false;
ListCell* l = NULL;
foreach (l, sortEntryList) {
OrderSiblingSortEntry *entry = (OrderSiblingSortEntry *)lfirst(l);
get_sort_group_operators(exprType((Node*)entry->tle->expr),
entry->sortCmpOp[SORTCMP_LT],
entry->sortCmpOp[SORTCMP_EQ],
entry->sortCmpOp[SORTCMP_GT],
&sortoplt, &sortopeq, &sortopgt, &hashable);
Oid sortop = InvalidOid;
if (entry->sortCmpOp[SORTCMP_LT]) {
sortop = sortoplt;
} else if (entry->sortCmpOp[SORTCMP_GT]) {
sortop = sortopgt;
} else {
/* we shouldn't get here */
sortop = sortopeq;
}
sortColIdx[numsortkeys] = entry->tle->resno;
sortOperators[numsortkeys] = sortop;
collations[numsortkeys] = exprCollation((Node*)entry->tle->expr);
nullsFirst[numsortkeys] = entry->sortByNullsFirst;
numsortkeys++;
}
sort = make_sort(root, lefttree, numsortkeys, sortColIdx,
sortOperators, collations, nullsFirst, limit_tuples);
return sort;
}
static bool IsNullsFirst(SortBy *sortby)
{
Assert(sortby != NULL);
bool ret = false;
bool reverse = (sortby->sortby_dir == SORTBY_DESC);
switch (sortby->sortby_nulls) {
case SORTBY_NULLS_DEFAULT:
/* NULLS FIRST is default for DESC; other way for ASC */
ret = reverse;
break;
case SORTBY_NULLS_FIRST:
ret = true;
break;
case SORTBY_NULLS_LAST:
ret = false;
break;
default:
ereport(ERROR,
(errcode(ERRCODE_UNEXPECTED_NODE_STATE),
errmsg("unrecognized sortby_nulls: %d", sortby->sortby_nulls)));
break;
}
return ret;
}
/*
* @Brief: Generate sort key under recursive union according siblings sort key
* select * from t1 start with...connect by...order siblings by c1,c2,c3
* the plan like this:
* ------------------QUERY PLAN--------------------
* > StartWithOP
* > Recursive Union
* > Sort Key, sort by c1, c2, c3 <<<<< we are have
* > Seqscan
* > Sort Key, sort by c1, c2, c3 <<<<< we are have
* > Seqscan
*/
static Sort *CreateSortPlanUnderRU(PlannerInfo* root, Plan* lefttree, List *siblings, double limit_tuples)
{
Sort *sort = NULL;
List *sortEntryList = NIL;
ListCell *lc = NULL;
ListCell *lc1 = NULL;
foreach (lc, siblings) {
SortBy *sb = (SortBy *)lfirst(lc);
char *colname = GetOrderSiblingsColName(root, sb, lefttree);
if (colname == NULL) {
ereport(WARNING,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("Order siblings by clause has unexpected key.")));
continue;
}
bool found = false;
/* search targetlist */
foreach (lc1, lefttree->targetlist) {
TargetEntry *tle = (TargetEntry *)lfirst(lc1);
if (tle->resname == NULL) {
continue;
}
/* one more fix name */
char *label = strrchr(tle->resname, '@');
label += 1;
label = pstrdup(label);
if (pg_strcasecmp(label, colname) == 0) {
found = true;
OrderSiblingSortEntry *entry =
CreateOrderSiblingSortEntry(tle,sb->sortby_dir);
entry->sortByNullsFirst = IsNullsFirst(sb);
sortEntryList = lappend(sortEntryList, entry);
if (u_sess->attr.attr_sql.enable_startwith_debug) {
elog(WARNING, "Good we got siblings sort key under RU.");
}
}
}
if (!found) {
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmodule(MOD_OPT),
errmsg("Siblings sort entry not found"),
errdetail("Column %s not found or not allowed here", colname),
errcause("Incorrect query input"),
erraction("Please check and revise your query")));
}
}
if (sortEntryList == NIL) {
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmodule(MOD_OPT),
errmsg("Invalid order siblings by clause"),
errdetail("Siblings sort entry not found"),
errcause("Incorrect query input"),
erraction("Please check and revise your query")));
}
sort = CreateSiblingsSortPlan(root, lefttree, sortEntryList, limit_tuples);
/* Free sort entries */
list_free_deep(sortEntryList);
return sort;
}
/*
* --------------------------------------------------------------------------------------
* fix WorkTableScan's targetlist
* --------------------------------------------------------------------------------------
*/
/*
* @Brief: push down all pseudo columns into plan node access (start from topNode
* end to botNode)
*/
void PushDownFullPseudoTargetlist(PlannerInfo *root, Plan *topNode, Plan *botNode,
List *fullEntryList)
{
Assert (fullEntryList != NIL);
PlanAccessPathSearchContext ctx;
errno_t rc = EOK;
rc = memset_s(&ctx, sizeof(PlanAccessPathSearchContext), 0, sizeof(PlanAccessPathSearchContext));
securec_check(rc, "\0", "\0");
ctx.topNode = topNode;
ctx.botNode = botNode;
ctx.fullEntryList = fullEntryList;
for (int i = 0; i < MAX_PLAN_DEPTH; i++) {
ctx.planStack.value_array[i] = NULL;
ctx.varnoStack.value_array[i] = 0;
}
ctx.planStack.top = -1;
ctx.varnoStack.top = -1;
ctx.done = false;
ctx.numsPrevTlist = -1;
/*
* Get the plan search path and add pseudo entry to let pseudo content return
* along with executor iteration normally.
*/
GetWorkTableScanPlanPath(root, (Plan *)topNode, &ctx);
Assert (ctx.planStack.top == ctx.varnoStack.top);
int nodeNums = ctx.planStack.top + 1;
if (nodeNums == 0) {
return;
}
StringInfoData si;
initStringInfo(&si);
/* Iterate the plan search path and add pseudo entry properly */
Plan *plan = NULL;
Index varno = 0;
while (nodeNums > 0) {
plan = StackNodePop(&ctx.planStack);
varno = StackVarnoPop(&ctx.varnoStack);
Assert (plan != NULL && varno > 0);
/* bind current node with proper pseudo entry info */
(void)BindPlanNodePseudoEntries(root, plan, varno, &ctx);
/* record current numbers of tlist */
ctx.numsPrevTlist = list_length(plan->targetlist);
/* build debug path string */
appendStringInfo(&si, " -> %s(tlist_len:%d)", nodeTagToString(nodeTag(plan)),
list_length(plan->targetlist));
nodeNums--;
}
if (u_sess->attr.attr_sql.enable_startwith_debug) {
elog(WARNING, "Pushdown pseudo_tlist >>>>> [%s]", si.data);
}
pfree_ext(si.data);
return;
}
/*
* --------------------------------------------------------------------------------------
* @Brief: Fix Array Internal Entry based on current targetlist level
* --------------------------------------------------------------------------------------
*/
static void FixArrayInternalEntry(List *targetlsit)
{
ListCell *lc1 = NULL;
ListCell *lc2 = NULL;
foreach(lc1, targetlsit) {
TargetEntry *entry = (TargetEntry *)lfirst(lc1);
if (entry->resname != NULL &&
(strstr(entry->resname, "array_key_") ||
strstr(entry->resname, "array_col_"))) {
int varno = ((Var *)entry->expr)->varno;
int attno = entry->resname[10] - '0';
int resno = 0;
foreach(lc2, targetlsit) {
TargetEntry *entry2 = (TargetEntry *)lfirst(lc2);
if (GetPseudoColumnType(entry2) == SWCOL_REGULAR) {
int varno2 = ((Var *)entry2->expr)->varno;
int attno2 = ((Var *)entry2->expr)->varattno;
if (varno == varno2 && attno2 == attno) {
resno = entry2->resno;
break;
}
}
}
char newArrayName[NAMEDATALEN];
errno_t rc = memset_s(newArrayName, NAMEDATALEN, 0, NAMEDATALEN);
securec_check(rc, "\0", "\0");
if (strstr(entry->resname, "array_key_")) {
rc = sprintf_s(newArrayName, NAMEDATALEN, "array_key_%d", resno);
securec_check_ss(rc, "\0", "\0");
} else if (strstr(entry->resname, "array_col_")) {
rc = sprintf_s(newArrayName, NAMEDATALEN, "array_col_%d", resno);
securec_check_ss(rc, "\0", "\0");
}
entry->resname = pstrdup(newArrayName);
}
}
return;
}
/*
* --------------------------------------------------------------------------------------
* @Brief: Determine if a given pseudo target entry exits in given targetlist, the term
* "exists" says with identical varno/varattno
* --------------------------------------------------------------------------------------
*/
static bool IsPseudoInternalEntryExists(List *targetlist, TargetEntry *tle)
{
bool result = false;
ListCell *lc = NULL;
Assert (tle != NULL);
/*
* Exist emtry targetlist during start with...connect by push down pseudo columns.
* e.x
* Select * from (select t1.c1 as num from t1 join t2 on true) as ss, t3
* start with ss.num = t3.c2
* connect by prior t3.c1 = t3.c3;
*
* In this case, if we have plan like
* Nestloop1 --> t1
* --> NestLoop2 --> t2
* --> worktable
*
* Then the NestLoop2 don't have any targetlist, but we also should
* inherit targetlist from wortable scan.
* */
if (targetlist == NULL) {
return result;
}
foreach (lc, targetlist) {
TargetEntry *curEntry = (TargetEntry *)lfirst(lc);
if (GetPseudoColumnType(curEntry) == SWCOL_REGULAR) {
/*
* skip regular entry, we only check special entries e.g. pseodu return column,
* internal entry
*/
continue;
}
Assert (IsA(tle->expr, Var));
if (pg_strcasecmp(curEntry->resname, tle->resname) == 0) {
result = true;
break;
}
}
return result;
}
/*
* --------------------------------------------------------------------------------------
* @brief: Add each pseudo entry to arget plan node
* --------------------------------------------------------------------------------------
*/
static void AddPseudoEntries(Plan *plan, Index relid, PlanAccessPathSearchContext *context)
{
ListCell *lc = NULL;
List *fullEntryList = context->fullEntryList;
Assert (plan != NULL && relid > 0 && fullEntryList != NIL);
int index = list_length(plan->targetlist);
int attno = 0;
bool adapt = false;
/* caculate PseudoColumn varattno from prev plan targetlist */
if (context->numsPrevTlist != -1) {
attno = context->numsPrevTlist - list_length(fullEntryList);
adapt = true;
}
/* Only add entry that does not added before */
foreach (lc, fullEntryList) {
TargetEntry *entry = (TargetEntry *)copyObject((TargetEntry *)lfirst(lc));
/*
* In "pseudo targetlist" push down process, we are going to avoid adding
* duplicate entry we do such kind of check, not-exit puls resno is appended
* at tail
*/
if (!IsPseudoInternalEntryExists(plan->targetlist, entry)) {
/*
* The target entry's resno,varno,varattno is created in CteScan planing stage,
* before we add it to curernt plan, we need do proper resno adjustment
*/
Assert (IsA(entry->expr, Var));
index++;
((Var *)entry->expr)->varno = relid;
if (adapt) {
attno++;
((Var *)entry->expr)->varattno = attno;
}
entry->resno = index;
plan->targetlist = lappend(plan->targetlist, entry);
}
}
if (context->botNode != NULL) {
FixArrayInternalEntry(plan->targetlist);
}
return;
}
/*
* --------------------------------------------------------------------------------------
* @brief: Add pseudo entries to arget plan node
* --------------------------------------------------------------------------------------
*/
static void BindPlanNodePseudoEntries(PlannerInfo *root, Plan *plan,
Index varno, PlanAccessPathSearchContext *context)
{
ListCell *lc = NULL;
switch (nodeTag(plan)) {
case T_RecursiveUnion: {
/*
* for recursive-union, besides do proper pseudo entry adding, we need build
* a separate list to help tupleslot-conversion(RuScan->StartWithOp)
*/
RecursiveUnion *ruplan = (RecursiveUnion *)plan;
/*
* Already add pseudo entry to RecursiveUnion once order siblings by exist,
* so we don't need add pseudo entry again.
*/
if (ruplan->internalEntryList != NULL) {
break;
}
AddPseudoEntries(plan, varno, context);
foreach (lc, context->fullEntryList) {
TargetEntry *entry = (TargetEntry *)copyObject((TargetEntry *)lfirst(lc));
if (IsPseudoInternalTargetEntry(entry)) {
ruplan->internalEntryList = lappend(ruplan->internalEntryList, entry);
}
}
break;
}
/* process regular case */
case T_Hash:
case T_HashJoin:
case T_SubqueryScan:
case T_CteScan:
case T_NestLoop:
case T_MergeJoin:
case T_Sort:
case T_Agg:
case T_BaseResult:
case T_Material:
case T_Append:
case T_Limit:
case T_Unique:
case T_WindowAgg:
case T_WorkTableScan: {
AddPseudoEntries(plan, varno, context);
break;
}
default: {
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmodule(MOD_OPT),
errmsg("%s is not supported in start with / connect by clauses", nodeTagToString(nodeTag(plan))),
errdetail("%s is not suppoted", nodeTagToString(nodeTag(plan))),
errcause("Input unsupported feature"),
erraction("NA")));
}
}
}
/*
* --------------------------------------------------------------------------------------
* @Brief: Generate a minimal set of plan-path reaching WTScan and to add pseudo entry,
* take example as follow: the generate path:
* RecursiveUnion -> HashJoin -> Hash -> WorkTableScan
*
* CteScan
* /
* StartWithOp
* /
* RecursiveUnion >>> CONVERT TO >>>>>>> RecursiveUnion
* / \ \
* SeqScan HashJoin HashJoin
* / \ \
* SeqScan Hash Hash
* / /
* WorktableScan <<<< target WorkTableScan
* --------------------------------------------------------------------------------------
*/
static void GetWorkTableScanPlanPath(PlannerInfo *root, Plan *node,
PlanAccessPathSearchContext *context)
{
StackNode *planStack = &context->planStack;
StackVarno *varnoStack = &context->varnoStack;
if (node == NULL) {
return;
}
if (context->done) {
return;
}
/* enqueue() */
StackNodePush(planStack, node);
switch (nodeTag(node)) {
case T_CteScan: {
CteScan *ctescan = (CteScan *)node;
if ((Node *)context->botNode == (Node *)ctescan) {
context->done = true;
Assert (context->relid == 0);
context->relid = ctescan->scan.scanrelid;
StackVarnoPush(varnoStack, ctescan->scan.scanrelid);
}
}
break;
case T_WorkTableScan: {
WorkTableScan *wtscan = (WorkTableScan *)node;
/* mark finish and to exit the iteration call stack immediately */
if (context->botNode == NULL) {
context->done = true;
/* set relid in current subquery level */
Assert (context->relid == 0);
context->relid = wtscan->scan.scanrelid;
StackVarnoPush(varnoStack, wtscan->scan.scanrelid);
}
}
break;
case T_VecSubqueryScan:
case T_SubqueryScan: {
SubqueryScan *sq = (SubqueryScan *)node;
StackVarnoPush(varnoStack, sq->scan.scanrelid);
GetWorkTableScanPlanPath(root, sq->subplan, context);
if (!context->done) {
StackVarnoPop(varnoStack);
}
}
break;
default: {
Plan *lplan = outerPlan(node);
Plan *rplan = innerPlan(node);
/*
* We need handle a case where RecursiveUnion's inner branch is BaseResult
* node, normally this happens a connectByExpr is evaluate as FALSE, instad
* of WT-join a BaseResult node is planned, e.g.
* e.g.
* [QUERY]
* SELECT * FROM test_hcb_ptb t1
* START WITH id=141
* CONNECT BY (prior pid)=id and prior pid>10 and 1=0;
*
* [PLAN]
* QUERY PLAN
* ------------------------------------------------------
* CTE Scan on tmp_reuslt
* CTE tmp_reuslt
* -> StartWith Operator
* Start With pseudo atts: RUITR, array_key_9
* -> Recursive Union
* -> Seq Scan on test_hcb_ptb
* Filter: (id = 141)
* -> Result
* One-Time Filter: false
* (9 rows)
*
*
*/
if (IsA(node, RecursiveUnion) && IsA(rplan, BaseResult) &&
context->botNode == NULL) {
context->done = true;
StackVarnoPush(varnoStack, INNER_VAR);
/* print-out debug information */
ereport(DEBUG1,
(errmodule(MOD_OPT_PLANNER), errmsg("SWCB query %s does not generate WTScan",
t_thrd.postgres_cxt.debug_query_string)));
break;
}
/*
* Before drill down into outer/inner plan tree, we set varno as OUTER_VAR/INNER for
* current level of plan node, as suppose the next outer/inner plan will build the final
* plan access path
*/
if (!context->done) {
StackVarnoPush(varnoStack, OUTER_VAR);
}
GetWorkTableScanPlanPath(root, lplan, context);
if (!context->done) {
StackVarnoPop(varnoStack);
}
/* process right tree */
if (!context->done) {
/* set varno for current level of plan node, we need skip once lplan is done */
StackVarnoPush(varnoStack, INNER_VAR);
}
GetWorkTableScanPlanPath(root, rplan, context);
if (!context->done) {
StackVarnoPop(varnoStack);
}
}
}
/* dequeue() */
if (!context->done) {
StackNodePop(planStack);
}
return;
}
/*
* --------------------------------------------------------------------------------------
* @brief:
* We do some special post-planing work for each StartWithOp node, normally, invokced from
* top planning level(root->query_level == 1)'s subplans, detail as follow:
* 1. Block some unspported case identified at planning stage
* 2. Add internal targetlist(ruitr, array_key, array_col) for Startwith
* 3. DFX to support output internal columns from a start with converted CTE
*
*
* @Note: There are two cases of of pseudo entries push-down for internal targetlist
* case1: StartWithOp => WorkTableScan, level information is store in WTScan and can be
* return to RecursiveUnion
* case2: TOP-1/TOP => CteScan, internal information need pop up to query's targetlist level,
* so that connect_by_root(), sys_connect_by_path() can get proper information
*
* Result ---------------
* | |
* ... |
* | case2: (ruitr/array_key/array_col)
* CteScan |
* | |
* StartWithOp ---------------
* | |
* RecursiveUnion |
* | |
* HashJoin case1: (level/isleaf/iscycle，ruitr/array_key/array_col)
* | |
* ... |
* | |
* WorkTableScan ---------------
*
* --------------------------------------------------------------------------------------
*/
void ProcessStartWithOpMixWork(PlannerInfo *root, Plan *topplan,
PlannerInfo *subroot, StartWithOp *swplan)
{
Assert (IsA(swplan, StartWithOp));
/*
* 1. Build fullEntry from current StartWithOp node to "start with"
* WorkTable
*/
PushDownFullPseudoTargetlist(root, (Plan *)swplan->ruplan,
NULL, swplan->fullEntryList);
/*
* 2. Add internalEntryList to CteScan node to support SWCB functions, by defualt
* we add full internal entries, only do this when there is SWCB functions exits,
* where check the StartWithOp's colEntryList
*/
if (swplan->colEntryList != NIL) {
CteScan *cteplan = swplan->cteplan;
PushDownFullPseudoTargetlist(root, (Plan *)cteplan, (Plan *)cteplan,
swplan->internalEntryList);
}
/*
* 3. Removing the unnecessary "Internal Target Entry" created by PRC push-down,
* ruitr/array_key/array_col, normally this kind of entry only visible on
* CteScan node
*/
if (!u_sess->attr.attr_sql.enable_startwith_debug) {
List *newList = NIL;
ListCell *lc = NULL;
foreach (lc, topplan->targetlist) {
TargetEntry *entry = (TargetEntry *)lfirst(lc);
if (IsPseudoInternalTargetEntry(entry)) {
continue;
}
newList = lappend(newList, entry);
}
topplan->targetlist = newList;
}
return;
}
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