Files
openGauss-server/src/gausskernel/optimizer/rewrite/rewriteHandler.cpp
2020-12-28 11:43:01 +08:00

2893 lines
113 KiB
C++

/* -------------------------------------------------------------------------
*
* rewriteHandler.cpp
* Primary module of query rewriter.
*
* 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/rewrite/rewriteHandler.cpp
*
* -------------------------------------------------------------------------
*/
#include "postgres.h"
#include "knl/knl_variable.h"
#include "access/sysattr.h"
#include "catalog/pg_type.h"
#include "commands/trigger.h"
#include "foreign/fdwapi.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "parser/analyze.h"
#include "parser/parse_coerce.h"
#include "parser/parsetree.h"
#include "parser/parse_merge.h"
#include "rewrite/rewriteDefine.h"
#include "rewrite/rewriteHandler.h"
#include "rewrite/rewriteManip.h"
#include "rewrite/rewriteRlsPolicy.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/rel_gs.h"
#include "catalog/pg_constraint.h"
#include "catalog/namespace.h"
#ifdef PGXC
#include "pgxc/locator.h"
#include "pgxc/nodemgr.h"
#include "pgxc/pgxc.h"
#include "nodes/nodes.h"
#include "optimizer/planner.h"
#include "optimizer/var.h"
#include "tcop/tcopprot.h"
#include "tcop/utility.h"
#endif
/* We use a list of these to detect recursion in RewriteQuery */
typedef struct rewrite_event {
Oid relation; /* OID of relation having rules */
CmdType event; /* type of rule being fired */
} rewrite_event;
static bool acquireLocksOnSubLinks(Node* node, void* context);
static Query* rewriteRuleAction(
Query* parsetree, Query* rule_action, Node* rule_qual, int rt_index, CmdType event, bool* returning_flag);
static List* adjustJoinTreeList(Query* parsetree, bool removert, int rt_index);
static List* rewriteTargetListIU(List* targetList, CmdType commandType,
Relation target_relation, int result_rtindex, List** attrno_list);
static TargetEntry* process_matched_tle(TargetEntry* src_tle, TargetEntry* prior_tle, const char* attrName);
static Node* get_assignment_input(Node* node);
static void rewriteValuesRTE(RangeTblEntry* rte, Relation target_relation, List* attrnos);
static void rewriteTargetListUD(Query* parsetree, RangeTblEntry* target_rte, Relation target_relation);
static void markQueryForLocking(Query* qry, Node* jtnode, bool forUpdate, bool noWait, bool pushedDown);
static List* matchLocks(CmdType event, RuleLock* rulelocks, int varno, Query* parsetree);
static Query* fireRIRrules(Query* parsetree, List* activeRIRs, bool forUpdatePushedDown);
#ifdef PGXC
typedef struct pull_qual_vars_context {
List* varlist;
int sublevels_up;
int resultRelation;
bool noRepeat;
} pull_qual_vars_context;
static bool pull_qual_vars_walker(Node* node, pull_qual_vars_context* context);
#endif
/*
* AcquireRewriteLocks -
* Acquire suitable locks on all the relations mentioned in the Query.
* These locks will ensure that the relation schemas don't change under us
* while we are rewriting and planning the query.
*
* forUpdatePushedDown indicates that a pushed-down FOR UPDATE/SHARE applies
* to the current subquery, requiring all rels to be opened with RowShareLock.
* This should always be false at the start of the recursion.
*
* A secondary purpose of this routine is to fix up JOIN RTE references to
* dropped columns (see details below). Because the RTEs are modified in
* place, it is generally appropriate for the caller of this routine to have
* first done a copyObject() to make a writable copy of the querytree in the
* current memory context.
*
* This processing can, and for efficiency's sake should, be skipped when the
* querytree has just been built by the parser: parse analysis already got
* all the same locks we'd get here, and the parser will have omitted dropped
* columns from JOINs to begin with. But we must do this whenever we are
* dealing with a querytree produced earlier than the current command.
*
* About JOINs and dropped columns: although the parser never includes an
* already-dropped column in a JOIN RTE's alias var list, it is possible for
* such a list in a stored rule to include references to dropped columns.
* (If the column is not explicitly referenced anywhere else in the query,
* the dependency mechanism won't consider it used by the rule and so won't
* prevent the column drop.) To support get_rte_attribute_is_dropped(),
* we replace join alias vars that reference dropped columns with NULL Const
* nodes.
*
* (In PostgreSQL 8.0, we did not do this processing but instead had
* get_rte_attribute_is_dropped() recurse to detect dropped columns in joins.
* That approach had horrible performance unfortunately; in particular
* construction of a nested join was O(N^2) in the nesting depth.)
*/
void AcquireRewriteLocks(Query* parsetree, bool forUpdatePushedDown)
{
ListCell* l = NULL;
int rt_index;
/*
* First, process RTEs of the current query level.
*/
rt_index = 0;
foreach (l, parsetree->rtable) {
RangeTblEntry* rte = (RangeTblEntry*)lfirst(l);
Relation rel;
LOCKMODE lockmode;
List* newaliasvars = NIL;
Index curinputvarno;
RangeTblEntry* curinputrte = NULL;
ListCell* ll = NULL;
++rt_index;
switch (rte->rtekind) {
case RTE_RELATION:
/*
* Grab the appropriate lock type for the relation, and do not
* release it until end of transaction. This protects the
* rewriter and planner against schema changes mid-query.
*
* If the relation is the query's result relation, then we
* need RowExclusiveLock. Otherwise, check to see if the
* relation is accessed FOR UPDATE/SHARE or not. We can't
* just grab AccessShareLock because then the executor would
* be trying to upgrade the lock, leading to possible
* deadlocks.
*/
if (rt_index == parsetree->resultRelation)
lockmode = RowExclusiveLock;
else if (forUpdatePushedDown || get_parse_rowmark(parsetree, (unsigned int)rt_index) != NULL)
lockmode = RowShareLock;
else
lockmode = AccessShareLock;
rel = heap_open(rte->relid, lockmode);
/*
* While we have the relation open, update the RTE's relkind,
* just in case it changed since this rule was made.
*/
rte->relkind = rel->rd_rel->relkind;
heap_close(rel, NoLock);
break;
case RTE_JOIN:
/*
* Scan the join's alias var list to see if any columns have
* been dropped, and if so replace those Vars with NULL
* Consts.
*
* Since a join has only two inputs, we can expect to see
* multiple references to the same input RTE; optimize away
* multiple fetches.
*/
newaliasvars = NIL;
curinputvarno = 0;
curinputrte = NULL;
foreach (ll, rte->joinaliasvars) {
Var* aliasvar = (Var*)lfirst(ll);
/*
* If the list item isn't a simple Var, then it must
* represent a merged column, ie a USING column, and so it
* couldn't possibly be dropped, since it's referenced in
* the join clause. (Conceivably it could also be a NULL
* constant already? But that's OK too.)
*/
if (IsA(aliasvar, Var)) {
/*
* The elements of an alias list have to refer to
* earlier RTEs of the same rtable, because that's the
* order the planner builds things in. So we already
* processed the referenced RTE, and so it's safe to
* use get_rte_attribute_is_dropped on it. (This might
* not hold after rewriting or planning, but it's OK
* to assume here.)
*/
AssertEreport(aliasvar->varlevelsup == 0, MOD_OPT, "");
if (aliasvar->varno != curinputvarno) {
curinputvarno = aliasvar->varno;
curinputrte = rt_fetch(curinputvarno, parsetree->rtable);
}
if (get_rte_attribute_is_dropped(curinputrte, aliasvar->varattno)) {
/*
* can't use vartype here, since that might be a
* now-dropped type OID, but it doesn't really
* matter what type the Const claims to be.
*/
aliasvar = (Var*)makeNullConst(INT4OID, -1, InvalidOid);
}
}
newaliasvars = lappend(newaliasvars, aliasvar);
}
rte->joinaliasvars = newaliasvars;
break;
case RTE_SUBQUERY:
/*
* The subquery RTE itself is all right, but we have to
* recurse to process the represented subquery.
*/
AcquireRewriteLocks(
rte->subquery, (forUpdatePushedDown || get_parse_rowmark(parsetree,
(unsigned int)rt_index) != NULL));
break;
default:
/* ignore other types of RTEs */
break;
}
}
/* Recurse into subqueries in WITH */
foreach (l, parsetree->cteList) {
CommonTableExpr* cte = (CommonTableExpr*)lfirst(l);
AcquireRewriteLocks((Query*)cte->ctequery, false);
}
/*
* Recurse into sublink subqueries, too. But we already did the ones in
* the rtable and cteList.
*/
if (parsetree->hasSubLinks)
(void)query_tree_walker(parsetree, (bool (*)())acquireLocksOnSubLinks, NULL, QTW_IGNORE_RC_SUBQUERIES);
}
/*
* Walker to find sublink subqueries for AcquireRewriteLocks
*/
static bool acquireLocksOnSubLinks(Node* node, void* context)
{
if (node == NULL)
return false;
if (IsA(node, SubLink)) {
SubLink* sub = (SubLink*)node;
/* Do what we came for */
AcquireRewriteLocks((Query*)sub->subselect, false);
/* Fall through to process lefthand args of SubLink */
}
/*
* Do NOT recurse into Query nodes, because AcquireRewriteLocks already
* processed subselects of subselects for us.
*/
return expression_tree_walker(node, (bool (*)())acquireLocksOnSubLinks, context);
}
/*
* rewriteRuleAction -
* Rewrite the rule action with appropriate qualifiers (taken from
* the triggering query).
*
* Input arguments:
* parsetree - original query
* rule_action - one action (query) of a rule
* rule_qual - WHERE condition of rule, or NULL if unconditional
* rt_index - RT index of result relation in original query
* event - type of rule event
* Output arguments:
* *returning_flag - set TRUE if we rewrite RETURNING clause in rule_action
* (must be initialized to FALSE)
* Return value:
* rewritten form of rule_action
*/
static Query* rewriteRuleAction(
Query* parsetree, Query* rule_action, Node* rule_qual, int rt_index, CmdType event, bool* returning_flag)
{
int current_varno, new_varno;
int rt_length;
Query* sub_action = NULL;
Query** sub_action_ptr;
/*
* Make modifiable copies of rule action and qual (what we're passed are
* the stored versions in the relcache; don't touch 'em!).
*/
rule_action = (Query*)copyObject(rule_action);
rule_qual = (Node*)copyObject(rule_qual);
/*
* Acquire necessary locks and fix any deleted JOIN RTE entries.
*/
AcquireRewriteLocks(rule_action, false);
(void)acquireLocksOnSubLinks(rule_qual, NULL);
current_varno = rt_index;
rt_length = list_length(parsetree->rtable);
new_varno = PRS2_NEW_VARNO + rt_length;
/*
* Adjust rule action and qual to offset its varnos, so that we can merge
* its rtable with the main parsetree's rtable.
*
* If the rule action is an INSERT...SELECT, the OLD/NEW rtable entries
* will be in the SELECT part, and we have to modify that rather than the
* top-level INSERT (kluge!).
*/
sub_action = getInsertSelectQuery(rule_action, &sub_action_ptr);
OffsetVarNodes((Node*)sub_action, rt_length, 0);
OffsetVarNodes(rule_qual, rt_length, 0);
/* but references to OLD should point at original rt_index */
ChangeVarNodes((Node*)sub_action, PRS2_OLD_VARNO + rt_length, rt_index, 0);
ChangeVarNodes(rule_qual, PRS2_OLD_VARNO + rt_length, rt_index, 0);
/*
* Generate expanded rtable consisting of main parsetree's rtable plus
* rule action's rtable; this becomes the complete rtable for the rule
* action. Some of the entries may be unused after we finish rewriting,
* but we leave them all in place for two reasons:
*
* We'd have a much harder job to adjust the query's varnos if we
* selectively removed RT entries.
*
* If the rule is INSTEAD, then the original query won't be executed at
* all, and so its rtable must be preserved so that the executor will do
* the correct permissions checks on it.
*
* RT entries that are not referenced in the completed jointree will be
* ignored by the planner, so they do not affect query semantics. But any
* permissions checks specified in them will be applied during executor
* startup (see ExecCheckRTEPerms()). This allows us to check that the
* caller has, say, insert-permission on a view, when the view is not
* semantically referenced at all in the resulting query.
*
* When a rule is not INSTEAD, the permissions checks done on its copied
* RT entries will be redundant with those done during execution of the
* original query, but we don't bother to treat that case differently.
*
* NOTE: because planner will destructively alter rtable, we must ensure
* that rule action's rtable is separate and shares no substructure with
* the main rtable. Hence do a deep copy here.
*/
sub_action->rtable = list_concat((List*)copyObject(parsetree->rtable), sub_action->rtable);
/*
* There could have been some SubLinks in parsetree's rtable, in which
* case we'd better mark the sub_action correctly.
*/
if (parsetree->hasSubLinks && !sub_action->hasSubLinks) {
ListCell* lc = NULL;
foreach (lc, parsetree->rtable) {
RangeTblEntry* rte = (RangeTblEntry*)lfirst(lc);
switch (rte->rtekind) {
case RTE_RELATION:
sub_action->hasSubLinks = checkExprHasSubLink((Node*)rte->tablesample);
break;
case RTE_FUNCTION:
sub_action->hasSubLinks = checkExprHasSubLink(rte->funcexpr);
break;
case RTE_VALUES:
sub_action->hasSubLinks = checkExprHasSubLink((Node*)rte->values_lists);
break;
default:
/* other RTE types don't contain bare expressions */
break;
}
if (sub_action->hasSubLinks)
break; /* no need to keep scanning rtable */
}
}
/*
* Also, we might have absorbed some RTEs with RLS conditions into the
* sub_action. If so, mark it as hasRowSecurity, whether or not those
* RTEs will be referenced after we finish rewriting. (Note: currently
* this is a no-op because RLS conditions aren't added till later, but it
* seems like good future-proofing to do this anyway.)
*/
sub_action->hasRowSecurity = (sub_action->hasRowSecurity || parsetree->hasRowSecurity);
/*
* Each rule action's jointree should be the main parsetree's jointree
* plus that rule's jointree, but usually *without* the original rtindex
* that we're replacing (if present, which it won't be for INSERT). Note
* that if the rule action refers to OLD, its jointree will add a
* reference to rt_index. If the rule action doesn't refer to OLD, but
* either the rule_qual or the user query quals do, then we need to keep
* the original rtindex in the jointree to provide data for the quals. We
* don't want the original rtindex to be joined twice, however, so avoid
* keeping it if the rule action mentions it.
*
* As above, the action's jointree must not share substructure with the
* main parsetree's.
*/
if (sub_action->commandType != CMD_UTILITY) {
bool keeporig = false;
List* newjointree = NIL;
AssertEreport(sub_action->jointree != NULL, MOD_OPT, "");
keeporig = (!rangeTableEntry_used((Node*)sub_action->jointree, rt_index, 0)) &&
(rangeTableEntry_used(rule_qual, rt_index, 0) ||
rangeTableEntry_used(parsetree->jointree->quals, rt_index, 0));
newjointree = adjustJoinTreeList(parsetree, !keeporig, rt_index);
if (newjointree != NIL) {
/*
* If sub_action is a setop, manipulating its jointree will do no
* good at all, because the jointree is dummy. (Perhaps someday
* we could push the joining and quals down to the member
* statements of the setop?)
*/
if (sub_action->setOperations != NULL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("conditional UNION/INTERSECT/EXCEPT statements are not implemented")));
sub_action->jointree->fromlist = list_concat(newjointree, sub_action->jointree->fromlist);
/*
* There could have been some SubLinks in newjointree, in which
* case we'd better mark the sub_action correctly.
*/
if (parsetree->hasSubLinks && !sub_action->hasSubLinks)
sub_action->hasSubLinks = checkExprHasSubLink((Node*)newjointree);
}
}
/*
* If the original query has any CTEs, copy them into the rule action. But
* we don't need them for a utility action.
*/
if (parsetree->cteList != NIL && sub_action->commandType != CMD_UTILITY) {
ListCell* lc = NULL;
/*
* Annoying implementation restriction: because CTEs are identified by
* name within a cteList, we can't merge a CTE from the original query
* if it has the same name as any CTE in the rule action.
*
* This could possibly be fixed by using some sort of internally
* generated ID, instead of names, to link CTE RTEs to their CTEs.
*/
foreach (lc, parsetree->cteList) {
CommonTableExpr* cte = (CommonTableExpr*)lfirst(lc);
ListCell* lc2 = NULL;
foreach (lc2, sub_action->cteList) {
CommonTableExpr* cte2 = (CommonTableExpr*)lfirst(lc2);
if (strcmp(cte->ctename, cte2->ctename) == 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("WITH query name \"%s\" appears in both a rule action and the query being rewritten",
cte->ctename)));
}
}
/* OK, it's safe to combine the CTE lists */
sub_action->cteList = list_concat(sub_action->cteList, (List*)copyObject(parsetree->cteList));
}
/*
* Event Qualification forces copying of parsetree and splitting into two
* queries one w/rule_qual, one w/NOT rule_qual. Also add user query qual
* onto rule action
*/
AddQual(sub_action, rule_qual);
AddQual(sub_action, parsetree->jointree->quals);
/*
* Rewrite new.attribute w/ right hand side of target-list entry for
* appropriate field name in insert/update.
*
* KLUGE ALERT: since ResolveNew returns a mutated copy, we can't just
* apply it to sub_action; we have to remember to update the sublink
* inside rule_action, too.
*/
if ((event == CMD_INSERT || event == CMD_UPDATE) && sub_action->commandType != CMD_UTILITY) {
sub_action = (Query*)ResolveNew((Node*)sub_action,
new_varno,
0,
rt_fetch(new_varno, sub_action->rtable),
parsetree->targetList,
event,
current_varno,
NULL);
if (sub_action_ptr != NULL)
*sub_action_ptr = sub_action;
else
rule_action = sub_action;
}
/*
* If rule_action has a RETURNING clause, then either throw it away if the
* triggering query has no RETURNING clause, or rewrite it to emit what
* the triggering query's RETURNING clause asks for. Throw an error if
* more than one rule has a RETURNING clause.
*/
if (!parsetree->returningList)
rule_action->returningList = NIL;
else if (rule_action->returningList) {
if (*returning_flag)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot have RETURNING lists in multiple rules")));
*returning_flag = true;
rule_action->returningList = (List*)ResolveNew((Node*)parsetree->returningList,
parsetree->resultRelation,
0,
rt_fetch(parsetree->resultRelation, parsetree->rtable),
rule_action->returningList,
CMD_SELECT,
0,
&rule_action->hasSubLinks);
/*
* There could have been some SubLinks in parsetree's returningList,
* in which case we'd better mark the rule_action correctly.
*/
if (parsetree->hasSubLinks && !rule_action->hasSubLinks)
rule_action->hasSubLinks = checkExprHasSubLink((Node*)rule_action->returningList);
}
return rule_action;
}
/*
* Copy the query's jointree list, and optionally attempt to remove any
* occurrence of the given rt_index as a top-level join item (we do not look
* for it within join items; this is OK because we are only expecting to find
* it as an UPDATE or DELETE target relation, which will be at the top level
* of the join). Returns modified jointree list --- this is a separate copy
* sharing no nodes with the original.
*/
static List* adjustJoinTreeList(Query* parsetree, bool removert, int rt_index)
{
List* newjointree = (List*)copyObject(parsetree->jointree->fromlist);
ListCell* l = NULL;
if (removert) {
foreach (l, newjointree) {
RangeTblRef* rtr = (RangeTblRef*)lfirst(l);
if (IsA(rtr, RangeTblRef) && rtr->rtindex == rt_index) {
newjointree = list_delete_ptr(newjointree, rtr);
/*
* foreach is safe because we exit loop after list_delete...
*/
break;
}
}
}
return newjointree;
}
/*
* rewriteTargetListIU - rewrite INSERT/UPDATE targetlist into standard form
*
* This has the following responsibilities:
*
* 1. For an INSERT, add tlist entries to compute default values for any
* attributes that have defaults and are not assigned to in the given tlist.
* (We do not insert anything for default-less attributes, however. The
* planner will later insert NULLs for them, but there's no reason to slow
* down rewriter processing with extra tlist nodes.) Also, for both INSERT
* and UPDATE, replace explicit DEFAULT specifications with column default
* expressions.
*
* 2. For an UPDATE on a view, add tlist entries for any unassigned-to
* attributes, assigning them their old values. These will later get
* expanded to the output values of the view. (This is equivalent to what
* the planner's expand_targetlist() will do for UPDATE on a regular table,
* but it's more convenient to do it here while we still have easy access
* to the view's original RT index.)
*
* 3. Merge multiple entries for the same target attribute, or declare error
* if we can't. Multiple entries are only allowed for INSERT/UPDATE of
* portions of an array or record field, for example
* UPDATE table SET foo[2] = 42, foo[4] = 43;
* We can merge such operations into a single assignment op. Essentially,
* the expression we want to produce in this case is like
* foo = array_set(array_set(foo, 2, 42), 4, 43)
*
* 4. Sort the tlist into standard order: non-junk fields in order by resno,
* then junk fields (these in no particular order).
*
* We must do items 1,2,3 before firing rewrite rules, else rewritten
* references to NEW.foo will produce wrong or incomplete results. Item 4
* is not needed for rewriting, but will be needed by the planner, and we
* can do it essentially for free while handling the other items.
*
* If attrno_list isn't NULL, we return an additional output besides the
* rewritten targetlist: an integer list of the assigned-to attnums, in
* order of the original tlist's non-junk entries. This is needed for
* processing VALUES RTEs.
*/
static List* rewriteTargetListIU(List* targetList, CmdType commandType, Relation target_relation,
int result_rtindex, List** attrno_list)
{
TargetEntry** new_tles;
List* new_tlist = NIL;
List* junk_tlist = NIL;
Form_pg_attribute att_tup;
int attrno, next_junk_attrno, numattrs;
ListCell* temp = NULL;
if (attrno_list != NULL) /* initialize optional result list */
*attrno_list = NIL;
/*
* We process the normal (non-junk) attributes by scanning the input tlist
* once and transferring TLEs into an array, then scanning the array to
* build an output tlist. This avoids O(N^2) behavior for large numbers
* of attributes.
*
* Junk attributes are tossed into a separate list during the same tlist
* scan, then appended to the reconstructed tlist.
*/
numattrs = RelationGetNumberOfAttributes(target_relation);
new_tles = (TargetEntry**)palloc0(numattrs * sizeof(TargetEntry*));
next_junk_attrno = numattrs + 1;
foreach (temp, targetList) {
TargetEntry* old_tle = (TargetEntry*)lfirst(temp);
if (!old_tle->resjunk) {
/* Normal attr: stash it into new_tles[] */
attrno = old_tle->resno;
if (attrno < 1 || attrno > numattrs) {
ereport(ERROR,
(errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("bogus resno %d in targetlist", attrno)));
}
att_tup = target_relation->rd_att->attrs[attrno - 1];
/* put attrno into attrno_list even if it's dropped */
if (attrno_list != NULL)
*attrno_list = lappend_int(*attrno_list, attrno);
/* We can (and must) ignore deleted attributes */
if (att_tup->attisdropped)
continue;
/* Merge with any prior assignment to same attribute */
new_tles[attrno - 1] = process_matched_tle(old_tle, new_tles[attrno - 1], NameStr(att_tup->attname));
} else {
/*
* Copy all resjunk tlist entries to junk_tlist, and assign them
* resnos above the last real resno.
*
* Typical junk entries include ORDER BY or GROUP BY expressions
* (are these actually possible in an INSERT or UPDATE?), system
* attribute references, etc.
*
* Get the resno right, but don't copy unnecessarily
*/
if (old_tle->resno != next_junk_attrno) {
old_tle = flatCopyTargetEntry(old_tle);
old_tle->resno = next_junk_attrno;
}
junk_tlist = lappend(junk_tlist, old_tle);
next_junk_attrno++;
}
}
for (attrno = 1; attrno <= numattrs; attrno++) {
TargetEntry* new_tle = new_tles[attrno - 1];
att_tup = target_relation->rd_att->attrs[attrno - 1];
/* We can (and must) ignore deleted attributes */
if (att_tup->attisdropped)
continue;
/*
* Handle the two cases where we need to insert a default expression:
* it's an INSERT and there's no tlist entry for the column, or the
* tlist entry is a DEFAULT placeholder node.
*/
if ((new_tle == NULL && commandType == CMD_INSERT) ||
(new_tle != NULL && new_tle->expr != NULL && IsA(new_tle->expr, SetToDefault))) {
Node* new_expr = NULL;
new_expr = build_column_default(target_relation, attrno, true);
/*
* If there is no default (ie, default is effectively NULL), we
* can omit the tlist entry in the INSERT case, since the planner
* can insert a NULL for itself, and there's no point in spending
* any more rewriter cycles on the entry. But in the UPDATE case
* we've got to explicitly set the column to NULL.
*/
if (new_expr == NULL) {
if (commandType == CMD_INSERT)
new_tle = NULL;
else {
new_expr = (Node*)makeConst(att_tup->atttypid,
-1,
att_tup->attcollation,
att_tup->attlen,
(Datum)0,
true, /* isnull */
att_tup->attbyval);
/* this is to catch a NOT NULL domain constraint */
new_expr = coerce_to_domain(
new_expr, InvalidOid, -1, att_tup->atttypid, COERCE_IMPLICIT_CAST, -1, false, false);
}
}
if (new_expr != NULL)
new_tle = makeTargetEntry((Expr*)new_expr, (int16)attrno, pstrdup(NameStr(att_tup->attname)), false);
}
/*
* For an UPDATE on a view, provide a dummy entry whenever there is no
* explicit assignment.
*/
if (new_tle == NULL && commandType == CMD_UPDATE && target_relation->rd_rel->relkind == RELKIND_VIEW) {
Node* new_expr = NULL;
new_expr = (Node*)makeVar(
result_rtindex, attrno, att_tup->atttypid, att_tup->atttypmod, att_tup->attcollation, 0);
new_tle = makeTargetEntry((Expr*)new_expr, (int16)attrno, pstrdup(NameStr(att_tup->attname)), false);
}
if (new_tle != NULL)
new_tlist = lappend(new_tlist, new_tle);
}
pfree_ext(new_tles);
targetList = list_concat(new_tlist, junk_tlist);
return targetList;
}
/*
* Convert a matched TLE from the original tlist into a correct new TLE.
*
* This routine detects and handles multiple assignments to the same target
* attribute. (The attribute name is needed only for error messages.)
*/
static TargetEntry* process_matched_tle(TargetEntry* src_tle, TargetEntry* prior_tle, const char* attrName)
{
TargetEntry* result = NULL;
Node* src_expr = NULL;
Node* prior_expr = NULL;
Node* src_input = NULL;
Node* prior_input = NULL;
Node* priorbottom = NULL;
Node* newexpr = NULL;
errno_t errorno = EOK;
if (prior_tle == NULL) {
/*
* Normal case where this is the first assignment to the attribute.
*/
return src_tle;
}
/* ----------
* Multiple assignments to same attribute. Allow only if all are
* FieldStore or ArrayRef assignment operations. This is a bit
* tricky because what we may actually be looking at is a nest of
* such nodes; consider
* UPDATE tab SET col.fld1.subfld1 = x, col.fld2.subfld2 = y
* The two expressions produced by the parser will look like
* FieldStore(col, fld1, FieldStore(placeholder, subfld1, x))
* FieldStore(col, fld2, FieldStore(placeholder, subfld2, x))
* However, we can ignore the substructure and just consider the top
* FieldStore or ArrayRef from each assignment, because it works to
* combine these as
* FieldStore(FieldStore(col, fld1,
* FieldStore(placeholder, subfld1, x)),
* fld2, FieldStore(placeholder, subfld2, x))
* Note the leftmost expression goes on the inside so that the
* assignments appear to occur left-to-right.
*
* For FieldStore, instead of nesting we can generate a single
* FieldStore with multiple target fields. We must nest when
* ArrayRefs are involved though.
* ----------
*/
src_expr = (Node*)src_tle->expr;
prior_expr = (Node*)prior_tle->expr;
src_input = get_assignment_input(src_expr);
prior_input = get_assignment_input(prior_expr);
if (src_input == NULL || prior_input == NULL || exprType(src_expr) != exprType(prior_expr)) {
ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("multiple assignments to same column \"%s\"", attrName)));
}
/*
* Prior TLE could be a nest of assignments if we do this more than once.
*/
priorbottom = prior_input;
for (;;) {
Node* newbottom = get_assignment_input(priorbottom);
if (newbottom == NULL) {
break; /* found the original Var reference */
}
priorbottom = newbottom;
}
if (!equal(priorbottom, src_input)) {
ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("multiple assignments to same column \"%s\"", attrName)));
}
/*
* Looks OK to nest 'em.
*/
size_t fstore_len = sizeof(FieldStore);
if (IsA(src_expr, FieldStore)) {
FieldStore* fstore = makeNode(FieldStore);
if (IsA(prior_expr, FieldStore)) {
/* combine the two */
errorno = memcpy_s(fstore, fstore_len, prior_expr, fstore_len);
securec_check(errorno, "\0", "\0");
fstore->newvals =
list_concat(list_copy(((FieldStore*)prior_expr)->newvals), list_copy(((FieldStore*)src_expr)->newvals));
fstore->fieldnums = list_concat(
list_copy(((FieldStore*)prior_expr)->fieldnums), list_copy(((FieldStore*)src_expr)->fieldnums));
} else {
/* general case, just nest 'em */
errorno = memcpy_s(fstore, fstore_len, src_expr, fstore_len);
securec_check(errorno, "\0", "\0");
fstore->arg = (Expr*)prior_expr;
}
newexpr = (Node*)fstore;
} else if (IsA(src_expr, ArrayRef)) {
ArrayRef* aref = makeNode(ArrayRef);
errorno = memcpy_s(aref, sizeof(ArrayRef), src_expr, sizeof(ArrayRef));
securec_check(errorno, "\0", "\0");
aref->refexpr = (Expr*)prior_expr;
newexpr = (Node*)aref;
} else {
ereport(ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("cannot happen")));
newexpr = NULL;
}
result = flatCopyTargetEntry(src_tle);
result->expr = (Expr*)newexpr;
return result;
}
/*
* If node is an assignment node, return its input; else return NULL
*/
static Node* get_assignment_input(Node* node)
{
if (node == NULL)
return NULL;
if (IsA(node, FieldStore)) {
FieldStore* fstore = (FieldStore*)node;
return (Node*)fstore->arg;
} else if (IsA(node, ArrayRef)) {
ArrayRef* aref = (ArrayRef*)node;
if (aref->refassgnexpr == NULL)
return NULL;
return (Node*)aref->refexpr;
}
return NULL;
}
/*
* Make an expression tree for the default value for a column.
*
* If there is no default, return a NULL instead.
* Add one input arg isInsertCmd to show if current statement is insert.
* If auto truncation function enabled and it is insert statement then
* we use this arg to determin if default should be casted explict.
*/
Node* build_column_default(Relation rel, int attrno, bool isInsertCmd)
{
TupleDesc rd_att = rel->rd_att;
Form_pg_attribute att_tup = rd_att->attrs[attrno - 1];
Oid atttype = att_tup->atttypid;
int32 atttypmod = att_tup->atttypmod;
Node* expr = NULL;
Oid exprtype;
/*
* Scan to see if relation has a default for this column.
*/
if (rd_att->constr && rd_att->constr->num_defval > 0) {
AttrDefault* defval = rd_att->constr->defval;
int ndef = rd_att->constr->num_defval;
while (--ndef >= 0) {
if (attrno == defval[ndef].adnum) {
/*
* Found it, convert string representation to node tree.
*/
expr = (Node*)stringToNode_skip_extern_fields(defval[ndef].adbin);
break;
}
}
}
if (expr == NULL) {
/*
* No per-column default, so look for a default for the type itself.
*/
expr = get_typdefault(atttype);
}
if (expr == NULL)
return NULL; /* No default anywhere */
/*
* Make sure the value is coerced to the target column type; this will
* generally be true already, but there seem to be some corner cases
* involving domain defaults where it might not be true. This should match
* the parser's processing of non-defaulted expressions --- see
* transformAssignedExpr().
*/
exprtype = exprType(expr);
expr = coerce_to_target_type(NULL, /* no UNKNOWN params here */
expr,
exprtype,
atttype,
atttypmod,
COERCION_ASSIGNMENT,
COERCE_IMPLICIT_CAST,
-1);
/*
* When td_compatible_truncation is set to on, this part of code will set column default
* value to isExplicte args to true, to let bpchar know one explict cast has been added to
* this default value already.
*/
if (u_sess->attr.attr_sql.td_compatible_truncation && DB_IS_CMPT(DB_CMPT_C) &&
isInsertCmd && (atttype == BPCHAROID || atttype == VARCHAROID) && expr != NULL) {
AssertEreport(IsA(expr, FuncExpr), MOD_OPT, "");
FuncExpr* fe = (FuncExpr*)expr;
Const* const_arg = (Const*)llast(fe->args);
if (IsA(const_arg, Const) && const_arg->consttype == BOOLOID)
const_arg->constvalue = (Datum) true;
}
if (expr == NULL)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("column \"%s\" is of type %s"
" but default expression is of type %s",
NameStr(att_tup->attname),
format_type_be(atttype),
format_type_be(exprtype)),
errhint("You will need to rewrite or cast the expression.")));
/*
* If there is nextval FuncExpr, we should lock the quoted sequence to avoid deadlock,
* this has beed done in transformFuncExpr. See lockNextvalOnCn for more details.
*/
(void)lockNextvalWalker(expr, NULL);
return expr;
}
/* Does VALUES RTE contain any SetToDefault items? */
static bool searchForDefault(RangeTblEntry* rte)
{
ListCell* lc = NULL;
foreach (lc, rte->values_lists) {
List* sublist = (List*)lfirst(lc);
ListCell* lc2 = NULL;
foreach (lc2, sublist) {
Node* col = (Node*)lfirst(lc2);
if (IsA(col, SetToDefault))
return true;
}
}
return false;
}
/*
* When processing INSERT ... VALUES with a VALUES RTE (ie, multiple VALUES
* lists), we have to replace any DEFAULT items in the VALUES lists with
* the appropriate default expressions. The other aspects of targetlist
* rewriting need be applied only to the query's targetlist proper.
*
* Note that we currently can't support subscripted or field assignment
* in the multi-VALUES case. The targetlist will contain simple Vars
* referencing the VALUES RTE, and therefore process_matched_tle() will
* reject any such attempt with "multiple assignments to same column".
*/
static void rewriteValuesRTE(RangeTblEntry* rte, Relation target_relation, List* attrnos)
{
List* newValues = NIL;
ListCell* lc = NULL;
/*
* Rebuilding all the lists is a pretty expensive proposition in a big
* VALUES list, and it's a waste of time if there aren't any DEFAULT
* placeholders. So first scan to see if there are any.
*/
if (!searchForDefault(rte))
return; /* nothing to do */
/* Check list lengths (we can assume all the VALUES sublists are alike) */
AssertEreport(list_length(attrnos) == list_length((const List*)linitial(rte->values_lists)), MOD_OPT, "");
newValues = NIL;
foreach (lc, rte->values_lists) {
List* sublist = (List*)lfirst(lc);
List* newList = NIL;
ListCell* lc2 = NULL;
ListCell* lc3 = NULL;
forboth(lc2, sublist, lc3, attrnos)
{
Node* col = (Node*)lfirst(lc2);
int attrno = lfirst_int(lc3);
if (IsA(col, SetToDefault)) {
Form_pg_attribute att_tup;
Node* new_expr = NULL;
att_tup = target_relation->rd_att->attrs[attrno - 1];
if (!att_tup->attisdropped)
new_expr = build_column_default(target_relation, attrno, true);
else
new_expr = NULL; /* force a NULL if dropped */
/*
* If there is no default (ie, default is effectively NULL),
* we've got to explicitly set the column to NULL.
*/
if (new_expr == NULL) {
new_expr = (Node*)makeConst(att_tup->atttypid,
-1,
att_tup->attcollation,
att_tup->attlen,
(Datum)0,
true, /* isnull */
att_tup->attbyval);
/* this is to catch a NOT NULL domain constraint */
new_expr = coerce_to_domain(
new_expr, InvalidOid, -1, att_tup->atttypid, COERCE_IMPLICIT_CAST, -1, false, false);
}
newList = lappend(newList, new_expr);
} else
newList = lappend(newList, col);
}
newValues = lappend(newValues, newList);
}
rte->values_lists = newValues;
}
#ifdef PGXC
/*
* pull_qual_vars(Node *node, int varno)
* Extract vars from quals belonging to resultRelation. This function is mainly
* taken from pull_qual_vars_clause(), but since the later does not peek into
* subquery, we need to write this walker.
*
* @param (in) varno:
* the varno of result relation
* pull_qual_vars will returen all vars in current level if do NOT set 'varno' param
*
* @return:
* (1) vars from quals belonging to resultRelation
* (2) all vars from quals if 'varno' is not set
*/
List* pull_qual_vars(Node* node, int varno, int flags, bool nonRepeat)
{
pull_qual_vars_context context;
context.varlist = NIL;
context.sublevels_up = 0;
context.resultRelation = varno;
context.noRepeat = nonRepeat;
(void)query_or_expression_tree_walker(node, (bool (*)())pull_qual_vars_walker, (void*)&context, flags);
return context.varlist;
}
static bool pull_qual_vars_walker(Node* node, pull_qual_vars_context* context)
{
if (node == NULL)
return false;
if (IsA(node, Var)) {
Var* var = (Var*)node;
/*
* Add only if this var belongs to the resultRelation and refers to the table
* from the same query.
* BUT==> if context->resultRelation is not set,
* all var(s) refers to the table from the same query will be included
*/
if ((context->resultRelation == 0 || var->varno == (Index)context->resultRelation) &&
var->varlevelsup == (Index)context->sublevels_up) {
if (context->noRepeat && list_member(context->varlist, var))
return false;
Var* newvar = (Var*)copyObject(var);
newvar->varlevelsup = 0;
context->varlist = lappend(context->varlist, newvar);
}
return false;
}
if (IsA(node, Query)) {
/* Recurse into RTE subquery or not-yet-planned sublink subquery */
bool result = false;
context->sublevels_up++;
result = query_tree_walker((Query*)node, (bool (*)())pull_qual_vars_walker, (void*)context, 0);
context->sublevels_up--;
return result;
}
return expression_tree_walker(node, (bool (*)())pull_qual_vars_walker, (void*)context);
}
#endif /* PGXC */
/*
* rewriteTargetListUD - rewrite UPDATE/DELETE targetlist as needed
*
* This function adds a "junk" TLE that is needed to allow the executor to
* find the original row for the update or delete. When the target relation
* is a regular table, the junk TLE emits the ctid attribute of the original
* row. When the target relation is a view, there is no ctid, so we instead
* emit a whole-row Var that will contain the "old" values of the view row.
* If it's a foreign table, we let the FDW decide what to add.
*
* For UPDATE queries, this is applied after rewriteTargetListIU. The
* ordering isn't actually critical at the moment.
*/
static void rewriteTargetListUD(Query* parsetree, RangeTblEntry* target_rte, Relation target_relation)
{
Var* var = NULL;
const char* attrname = NULL;
TargetEntry* tle = NULL;
#ifdef PGXC
List* var_list = NIL;
ListCell* elt = NULL;
/*
* In Postgres-XC, we need to evaluate quals of the parse tree and determine
* if they are Coordinator quals. If they are, their attribute need to be
* added to target list for evaluation. In case some are found, add them as
* junks in the target list. The junk status will be used by remote UPDATE
* planning to associate correct element to a clause.
* For DELETE, having such columns in target list helps to evaluate Quals
* correctly on Coordinator.
* This list could be reduced to keep only in target list the
* vars using Coordinator Quals.
*/
if (IS_PGXC_COORDINATOR && parsetree->jointree)
var_list = pull_qual_vars((Node*)parsetree->jointree, parsetree->resultRelation);
foreach (elt, var_list) {
Form_pg_attribute att_tup;
int numattrs = RelationGetNumberOfAttributes(target_relation);
var = (Var*)lfirst(elt);
/* Bypass in case of extra target items like ctid */
if (var->varattno < 1 || var->varattno > numattrs) {
if (var->varattno < 1) {
RangeTblEntry* rte = rt_fetch(var->varno, parsetree->rtable);
if (LOCATOR_TYPE_REPLICATED == GetLocatorType(rte->relid)) {
t_thrd.postmaster_cxt.forceNoSeparate = true;
}
parsetree->equalVars = lappend(parsetree->equalVars, copyObject(var));
}
continue;
}
att_tup = target_relation->rd_att->attrs[var->varattno - 1];
tle = makeTargetEntry(
(Expr*)var, (int16)(list_length(parsetree->targetList) + 1), pstrdup(NameStr(att_tup->attname)), true);
parsetree->targetList = lappend(parsetree->targetList, tle);
}
parsetree->equalVars = list_concat(
parsetree->equalVars, pull_qual_vars((Node*)parsetree->targetList, parsetree->resultRelation, 0, true));
if (IS_PGXC_COORDINATOR && RelationGetLocInfo(target_relation) &&
IsRelationReplicated(RelationGetLocInfo(target_relation)) && RelationIsRelation(target_relation)) {
int16* indexed_col = NULL;
int index_col_count = 0;
int counter = 0;
index_col_count = pgxc_find_primarykey(target_relation->rd_id, &indexed_col);
AssertEreport(index_col_count >= 0, MOD_OPT, "");
for (counter = 0; counter < index_col_count; counter++) {
AttrNumber att_no = indexed_col[counter];
Form_pg_attribute att_tup = NULL;
Node* new_expr = NULL;
TargetEntry* new_tle = NULL;
att_tup = target_relation->rd_att->attrs[att_no - 1];
new_expr = (Node*)makeVar((unsigned int)(parsetree->resultRelation), att_no, att_tup->atttypid,
att_tup->atttypmod, att_tup->attcollation, 0);
new_tle = makeTargetEntry(
(Expr*)new_expr, (int16)(list_length(parsetree->targetList) + 1), "xc_primary_key", true);
parsetree->targetList = lappend(parsetree->targetList, new_tle);
}
}
#endif
if (target_relation->rd_rel->relkind == RELKIND_RELATION || target_relation->rd_rel->relkind == RELKIND_MATVIEW) {
/*
* Emit CTID so that executor can find the row to update or delete.
*/
var = makeVar(
(unsigned int)(parsetree->resultRelation), SelfItemPointerAttributeNumber, TIDOID, -1, InvalidOid, 0);
attrname = "ctid";
} else if (target_relation->rd_rel->relkind == RELKIND_FOREIGN_TABLE) {
/*
* Let the foreign table's FDW add whatever junk TLEs it wants.
*/
FdwRoutine* fdwroutine = NULL;
fdwroutine = GetFdwRoutineForRelation(target_relation, false);
if (fdwroutine->AddForeignUpdateTargets != NULL)
fdwroutine->AddForeignUpdateTargets(parsetree, target_rte, target_relation);
return;
} else {
/*
* Emit whole-row Var so that executor will have the "old" view row to
* pass to the INSTEAD OF trigger.
*/
var = makeWholeRowVar(target_rte, (unsigned int)(parsetree->resultRelation), 0, false);
if (var == NULL) {
ereport(ERROR,(errcode(ERRCODE_UNDEFINED_FILE),
errmsg("Fail to get the previous view row.")));
return;
}
attrname = "wholerow";
}
tle = makeTargetEntry((Expr*)var, (int16)(list_length(parsetree->targetList) + 1), pstrdup(attrname), true);
parsetree->targetList = lappend(parsetree->targetList, tle);
/* if a partitioned table , need get tableOid column */
if (target_relation->rd_rel->relkind == RELKIND_RELATION &&
(RELATION_IS_PARTITIONED(target_relation) || RelationIsCUFormat(target_relation))) {
var = makeVar((unsigned int)(parsetree->resultRelation), TableOidAttributeNumber, OIDOID, -1, InvalidOid, 0);
attrname = "tableoid";
tle = makeTargetEntry((Expr*)var, (int16)(list_length(parsetree->targetList) + 1), pstrdup(attrname), true);
parsetree->targetList = lappend(parsetree->targetList, tle);
}
if (target_relation->rd_rel->relkind == RELKIND_RELATION && RELATION_HAS_BUCKET(target_relation)) {
var = makeVar((unsigned int)(parsetree->resultRelation), BucketIdAttributeNumber, INT2OID, -1, InvalidBktId, 0);
attrname = "tablebucketid";
tle = makeTargetEntry((Expr*)var, (int16)(list_length(parsetree->targetList) + 1), pstrdup(attrname), true);
parsetree->targetList = lappend(parsetree->targetList, tle);
}
#ifdef PGXC
/* Add further attributes required for Coordinator */
if (IS_PGXC_COORDINATOR && RelationGetLocInfo(target_relation) != NULL &&
target_relation->rd_rel->relkind == RELKIND_RELATION) {
/*
* If relation is non-replicated, we need also to identify the Datanode
* from where tuple is fetched.
*/
if (!IsRelationReplicated(RelationGetLocInfo(target_relation))) {
var = makeVar(
(unsigned int)(parsetree->resultRelation), XC_NodeIdAttributeNumber, INT4OID, -1, InvalidOid, 0);
tle = makeTargetEntry(
(Expr*)var, (int16)(list_length(parsetree->targetList) + 1), pstrdup("xc_node_id"), true);
parsetree->targetList = lappend(parsetree->targetList, tle);
}
/* For non-shippable triggers, we need OLD row. */
if (pgxc_trig_oldrow_reqd(target_relation, parsetree->commandType)) {
var = makeWholeRowVar(target_rte, (unsigned int)(parsetree->resultRelation), 0, false);
tle = makeTargetEntry(
(Expr*)var, (int16)(list_length(parsetree->targetList) + 1), pstrdup("wholerow"), true);
parsetree->targetList = lappend(parsetree->targetList, tle);
}
}
#endif
}
void rewriteTargetListMerge(Query* parsetree, Index result_relation, List* range_table)
{
Var* var = NULL;
const char* attrname = NULL;
TargetEntry* tle = NULL;
Relation rel;
/*
* The rewriter should have already ensured that the TLEs are in correct
* order; but we have to insert TLEs for any missing attributes.
*
* Scan the tuple description in the relation's relcache entry to make
* sure we have all the user attributes in the right order. We assume
* that the rewriter already acquired at least AccessShareLock on the
* relation, so we need no lock here.
*/
rel = heap_open(getrelid(result_relation, range_table), NoLock);
Assert(rel->rd_rel->relkind == RELKIND_RELATION);
parsetree->targetList = expandTargetTL(parsetree->targetList, parsetree);
/*
* Emit CTID so that executor can find the row to update or delete.
*/
var = makeVar((unsigned int)(parsetree->mergeTarget_relation), SelfItemPointerAttributeNumber, TIDOID, -1,
InvalidOid, 0);
attrname = "ctid";
tle = makeTargetEntry((Expr*)var, (int16)(list_length(parsetree->targetList) + 1), pstrdup(attrname), true);
parsetree->targetList = lappend(parsetree->targetList, tle);
/* We need add xc_node_id for MPP cluster mode, but only ctid for single datanode */
if (!IS_SINGLE_NODE) {
/*
* Emit xc_node_id so that executor can find the row to update or delete.
*/
var = makeVar(
(unsigned int)(parsetree->mergeTarget_relation), XC_NodeIdAttributeNumber, INT4OID, -1, InvalidOid, 0);
attrname = "xc_node_id";
tle = makeTargetEntry((Expr*)var, (int16)(list_length(parsetree->targetList) + 1), pstrdup(attrname), true);
parsetree->targetList = lappend(parsetree->targetList, tle);
}
/*
* If we are dealing with partitioned table, then emit TABLEOID so that
* executor can find the partition the row belongs to.
*/
if (RELATION_IS_PARTITIONED(rel) || RelationIsCUFormat(rel)) {
var = makeVar(
(unsigned int)(parsetree->mergeTarget_relation), TableOidAttributeNumber, OIDOID, -1, InvalidOid, 0);
attrname = "tableoid";
tle = makeTargetEntry((Expr*)var, (int16)(list_length(parsetree->targetList) + 1), pstrdup(attrname), true);
parsetree->targetList = lappend(parsetree->targetList, tle);
}
if (RELATION_HAS_BUCKET(rel)) {
var = makeVar(parsetree->mergeTarget_relation, BucketIdAttributeNumber, INT2OID, -1, InvalidBktId, 0);
attrname = "tablebucketid";
tle = makeTargetEntry((Expr*)var, (int16)(list_length(parsetree->targetList) + 1), pstrdup(attrname), true);
parsetree->targetList = lappend(parsetree->targetList, tle);
}
heap_close(rel, NoLock);
}
/*
* matchLocks -
* match the list of locks and returns the matching rules
*/
static List* matchLocks(CmdType event, RuleLock* rulelocks, int varno, Query* parsetree)
{
List* matching_locks = NIL;
int nlocks;
int i;
if (rulelocks == NULL)
return NIL;
if (parsetree->commandType != CMD_SELECT) {
if (parsetree->resultRelation != varno)
return NIL;
}
nlocks = rulelocks->numLocks;
for (i = 0; i < nlocks; i++) {
RewriteRule* oneLock = rulelocks->rules[i];
/*
* Suppress ON INSERT/UPDATE/DELETE rules that are disabled or
* configured to not fire during the current sessions replication
* role. ON SELECT rules will always be applied in order to keep views
* working even in LOCAL or REPLICA role.
*/
if (oneLock->event != CMD_SELECT) {
if (u_sess->attr.attr_common.SessionReplicationRole == SESSION_REPLICATION_ROLE_REPLICA) {
if (oneLock->enabled == RULE_FIRES_ON_ORIGIN || oneLock->enabled == RULE_DISABLED)
continue;
} else { /* ORIGIN or LOCAL ROLE */
if (oneLock->enabled == RULE_FIRES_ON_REPLICA || oneLock->enabled == RULE_DISABLED)
continue;
}
}
if (oneLock->event == event) {
if (parsetree->commandType != CMD_SELECT ||
(oneLock->attrno == -1 ? rangeTableEntry_used((Node*)parsetree, varno, 0)
: attribute_used((Node*)parsetree, varno, oneLock->attrno, 0)))
matching_locks = lappend(matching_locks, oneLock);
}
}
return matching_locks;
}
/*
* ApplyRetrieveRule - expand an ON SELECT rule
*/
static Query* ApplyRetrieveRule(Query* parsetree, RewriteRule* rule, int rt_index, bool relation_level,
Relation relation, List* activeRIRs, bool forUpdatePushedDown)
{
Query* rule_action = NULL;
RangeTblEntry* rte = NULL;
RangeTblEntry* subrte = NULL;
RowMarkClause* rc = NULL;
if (list_length(rule->actions) != 1) {
ereport(ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("expected just one rule action")));
}
if (rule->qual != NULL) {
ereport(
ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("cannot handle qualified ON SELECT rule")));
}
if (!relation_level) {
ereport(ERROR,
(errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("cannot handle per-attribute ON SELECT rule")));
}
if (rt_index == parsetree->resultRelation) {
/*
* We have a view as the result relation of the query, and it wasn't
* rewritten by any rule. This case is supported if there is an
* INSTEAD OF trigger that will trap attempts to insert/update/delete
* view rows. The executor will check that; for the moment just plow
* ahead. We have two cases:
*
* For INSERT, we needn't do anything. The unmodified RTE will serve
* fine as the result relation.
*
* For UPDATE/DELETE, we need to expand the view so as to have source
* data for the operation. But we also need an unmodified RTE to
* serve as the target. So, copy the RTE and add the copy to the
* rangetable. Note that the copy does not get added to the jointree.
* Also note that there's a hack in fireRIRrules to avoid calling this
* function again when it arrives at the copied RTE.
*/
if (parsetree->commandType == CMD_INSERT)
return parsetree;
else if (parsetree->commandType == CMD_UPDATE || parsetree->commandType == CMD_DELETE) {
RangeTblEntry* newrte = NULL;
rte = rt_fetch(rt_index, parsetree->rtable);
newrte = (RangeTblEntry*)copyObject(rte);
parsetree->rtable = (List*)lappend(parsetree->rtable, newrte);
parsetree->resultRelation = list_length(parsetree->rtable);
/*
* There's no need to do permissions checks twice, so wipe out the
* permissions info for the original RTE (we prefer to keep the
* bits set on the result RTE).
*/
rte->requiredPerms = 0;
rte->checkAsUser = InvalidOid;
rte->selectedCols = NULL;
rte->insertedCols = NULL;
rte->updatedCols = NULL;
/*
* For the most part, Vars referencing the view should remain as
* they are, meaning that they implicitly represent OLD values.
* But in the RETURNING list if any, we want such Vars to
* represent NEW values, so change them to reference the new RTE.
*
* Since ChangeVarNodes scribbles on the tree in-place, copy the
* RETURNING list first for safety.
*/
parsetree->returningList = (List*)copyObject(parsetree->returningList);
ChangeVarNodes((Node*)parsetree->returningList, rt_index, parsetree->resultRelation, 0);
/* Now, continue with expanding the original view RTE */
} else {
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("unrecognized commandType: %d", (int)parsetree->commandType)));
}
}
/*
* If FOR UPDATE/SHARE of view, be sure we get right initial lock on the
* relations it references.
*/
rc = get_parse_rowmark(parsetree, (unsigned int)rt_index);
forUpdatePushedDown = forUpdatePushedDown || (rc != NULL);
/*
* Make a modifiable copy of the view query, and acquire needed locks on
* the relations it mentions.
*/
rule_action = (Query*)copyObject(linitial(rule->actions));
AcquireRewriteLocks(rule_action, forUpdatePushedDown);
/*
* Recursively expand any view references inside the view.
*/
rule_action = fireRIRrules(rule_action, activeRIRs, forUpdatePushedDown);
/*
* Now, plug the view query in as a subselect, replacing the relation's
* original RTE.
*/
rte = rt_fetch(rt_index, parsetree->rtable);
rte->rtekind = RTE_SUBQUERY;
rte->relid = InvalidOid;
rte->security_barrier = RelationIsSecurityView(relation);
rte->subquery = rule_action;
rte->inh = false; /* must not be set for a subquery */
/*
* We move the view's permission check data down to its rangetable. The
* checks will actually be done against the OLD entry therein.
*/
subrte = rt_fetch(PRS2_OLD_VARNO, rule_action->rtable);
AssertEreport(subrte->relid == relation->rd_id, MOD_OPT, "");
subrte->requiredPerms = rte->requiredPerms;
subrte->checkAsUser = rte->checkAsUser;
subrte->selectedCols = rte->selectedCols;
subrte->insertedCols = rte->insertedCols;
subrte->updatedCols = rte->updatedCols;
rte->requiredPerms = 0; /* no permission check on subquery itself */
rte->checkAsUser = InvalidOid;
rte->selectedCols = NULL;
rte->insertedCols = NULL;
rte->updatedCols = NULL;
/*
* If FOR UPDATE/SHARE of view, mark all the contained tables as implicit
* FOR UPDATE/SHARE, the same as the parser would have done if the view's
* subquery had been written out explicitly.
*
* Note: we don't consider forUpdatePushedDown here; such marks will be
* made by recursing from the upper level in markQueryForLocking.
*/
if (rc != NULL)
markQueryForLocking(rule_action, (Node*)rule_action->jointree, rc->forUpdate, rc->noWait, true);
return parsetree;
}
/*
* Recursively mark all relations used by a view as FOR UPDATE/SHARE.
*
* This may generate an invalid query, eg if some sub-query uses an
* aggregate. We leave it to the planner to detect that.
*
* NB: this must agree with the parser's transformLockingClause() routine.
* However, unlike the parser we have to be careful not to mark a view's
* OLD and NEW rels for updating. The best way to handle that seems to be
* to scan the jointree to determine which rels are used.
*/
static void markQueryForLocking(Query* qry, Node* jtnode, bool forUpdate, bool noWait, bool pushedDown)
{
if (jtnode == NULL)
return;
if (IsA(jtnode, RangeTblRef)) {
int rti = ((RangeTblRef*)jtnode)->rtindex;
RangeTblEntry* rte = rt_fetch(rti, qry->rtable);
if (rte->rtekind == RTE_RELATION) {
applyLockingClause(qry, (unsigned int)rti, forUpdate, noWait, pushedDown);
rte->requiredPerms |= ACL_SELECT_FOR_UPDATE;
} else if (rte->rtekind == RTE_SUBQUERY) {
applyLockingClause(qry, rti, forUpdate, noWait, pushedDown);
/* FOR UPDATE/SHARE of subquery is propagated to subquery's rels */
markQueryForLocking(rte->subquery, (Node*)rte->subquery->jointree, forUpdate, noWait, true);
}
/* other RTE types are unaffected by FOR UPDATE */
} else if (IsA(jtnode, FromExpr)) {
FromExpr* f = (FromExpr*)jtnode;
ListCell* l = NULL;
foreach (l, f->fromlist)
markQueryForLocking(qry, (Node*)lfirst(l), forUpdate, noWait, pushedDown);
} else if (IsA(jtnode, JoinExpr)) {
JoinExpr* j = (JoinExpr*)jtnode;
markQueryForLocking(qry, j->larg, forUpdate, noWait, pushedDown);
markQueryForLocking(qry, j->rarg, forUpdate, noWait, pushedDown);
} else
ereport(ERROR,
(errmodule(MOD_OPT_REWRITE),
errcode(ERRCODE_DATA_CORRUPTED),
errmsg("unrecognized node type: %d", (int)nodeTag(jtnode))));
}
/*
* fireRIRonSubLink -
* Apply fireRIRrules() to each SubLink (subselect in expression) found
* in the given tree.
*
* NOTE: although this has the form of a walker, we cheat and modify the
* SubLink nodes in-place. It is caller's responsibility to ensure that
* no unwanted side-effects occur!
*
* This is unlike most of the other routines that recurse into subselects,
* because we must take control at the SubLink node in order to replace
* the SubLink's subselect link with the possibly-rewritten subquery.
*/
static bool fireRIRonSubLink(Node* node, List* activeRIRs)
{
if (node == NULL)
return false;
if (IsA(node, SubLink)) {
SubLink* sub = (SubLink*)node;
/* Do what we came for */
sub->subselect = (Node*)fireRIRrules((Query*)sub->subselect, activeRIRs, false);
/* Fall through to process lefthand args of SubLink */
}
/*
* Do NOT recurse into Query nodes, because fireRIRrules already processed
* subselects of subselects for us.
*/
return expression_tree_walker(node, (bool (*)())fireRIRonSubLink, (void*)activeRIRs);
}
/*
* fireRIRrules -
* Apply all RIR rules on each rangetable entry in a query
*/
static Query* fireRIRrules(Query* parsetree, List* activeRIRs, bool forUpdatePushedDown)
{
int origResultRelation = parsetree->resultRelation;
int rt_index;
ListCell* lc = NULL;
/*
* don't try to convert this into a foreach loop, because rtable list can
* get changed each time through...
*/
rt_index = 0;
while (rt_index < list_length(parsetree->rtable)) {
RangeTblEntry* rte = NULL;
Relation rel;
List* locks = NIL;
RuleLock* rules = NULL;
RewriteRule* rule = NULL;
int i;
++rt_index;
rte = rt_fetch(rt_index, parsetree->rtable);
/*
* A subquery RTE can't have associated rules, so there's nothing to
* do to this level of the query, but we must recurse into the
* subquery to expand any rule references in it.
*/
if (rte->rtekind == RTE_SUBQUERY) {
rte->subquery = fireRIRrules(
rte->subquery, activeRIRs, (forUpdatePushedDown || get_parse_rowmark(parsetree, rt_index) != NULL));
continue;
}
/*
* Joins and other non-relation RTEs can be ignored completely.
*/
if (rte->rtekind != RTE_RELATION) {
continue;
}
/*
* Always ignore RIR rules for materialized views referenced in
* queries. (This does not prevent refreshing MVs, since they aren't
* referenced in their own query definitions.)
*
* Note: in the future we might want to allow MVs to be conditionally
* expanded as if they were regular views, if they are not scannable.
* In that case this test would need to be postponed till after we've
* opened the rel, so that we could check its state.
*/
if (rte->relkind == RELKIND_MATVIEW)
continue;
/*
* If the table is not referenced in the query, then we ignore it.
* This prevents infinite expansion loop due to new rtable entries
* inserted by expansion of a rule. A table is referenced if it is
* part of the join set (a source table), or is referenced by any Var
* nodes, or is the result table.
*/
if (rt_index != parsetree->resultRelation && !rangeTableEntry_used((Node*)parsetree, rt_index, 0)) {
continue;
}
/*
* Also, if this is a new result relation introduced by
* ApplyRetrieveRule, we don't want to do anything more with it.
*/
if (rt_index == parsetree->resultRelation && rt_index != origResultRelation) {
continue;
}
/*
* We can use NoLock here since either the parser or
* AcquireRewriteLocks should have locked the rel already.
*/
rel = heap_open(rte->relid, NoLock);
/*
* Collect the RIR rules that we must apply
*/
rules = rel->rd_rules;
if (rules == NULL) {
heap_close(rel, NoLock);
continue;
}
for (i = 0; i < rules->numLocks; i++) {
rule = rules->rules[i];
if (rule->event != CMD_SELECT) {
continue;
}
if (rule->attrno > 0) {
/* per-attr rule; do we need it? */
if (!attribute_used((Node*)parsetree, rt_index, rule->attrno, 0))
continue;
}
locks = lappend(locks, rule);
}
/*
* If we found any, apply them --- but first check for recursion!
*/
if (locks != NIL) {
ListCell* l = NULL;
if (list_member_oid(activeRIRs, RelationGetRelid(rel))) {
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg(
"infinite recursion detected in rules for relation \"%s\"", RelationGetRelationName(rel))));
}
activeRIRs = lcons_oid(RelationGetRelid(rel), activeRIRs);
foreach (l, locks) {
rule = (RewriteRule*)lfirst(l);
parsetree = ApplyRetrieveRule(
parsetree, rule, rt_index, rule->attrno == -1, rel, activeRIRs, forUpdatePushedDown);
}
activeRIRs = list_delete_first(activeRIRs);
}
heap_close(rel, NoLock);
}
/* Recurse into subqueries in WITH */
foreach (lc, parsetree->cteList) {
CommonTableExpr* cte = (CommonTableExpr*)lfirst(lc);
cte->ctequery = (Node*)fireRIRrules((Query*)cte->ctequery, activeRIRs, false);
}
/*
* Recurse into sublink subqueries, too. But we already did the ones in
* the rtable and cteList.
*/
if (parsetree->hasSubLinks) {
(void)query_tree_walker(parsetree, (bool (*)())fireRIRonSubLink, (void*)activeRIRs, QTW_IGNORE_RC_SUBQUERIES);
}
/*
* Apply row level security policies. Do this work here because it
* requires special recursion detection if the new quals have sublink
* subqueries, and if we did it in the loop above query_tree_walker would
* then recurse into those quals a second time.
* Only bind R.L.S policies to plan on coordinator node like view. Currently
* R.L.S only suport SELECT, UPDATE, DELETE.
*/
if ((IS_PGXC_COORDINATOR || IS_SINGLE_NODE) &&
((parsetree->commandType == CMD_SELECT) || (parsetree->commandType == CMD_UPDATE) ||
(parsetree->commandType == CMD_DELETE))) {
rt_index = 0;
foreach (lc, parsetree->rtable) {
RangeTblEntry* rte = (RangeTblEntry*)lfirst(lc);
List* securityQuals = NIL;
bool hasRowSecurity = false;
bool hasSubLink = false;
rt_index++;
/* Row-Level-Security policy can only applied to normal
* relation(include partitioned relation)
*/
if ((rte->rtekind != RTE_RELATION) || (rte->relkind != RELKIND_RELATION)) {
continue;
}
Relation targetTable = relation_open(rte->relid, NoLock);
/* Fetch all R.L.S security quals that must be applied to this RTE */
GetRlsPolicies(parsetree, rte, targetTable, &securityQuals, rt_index, hasRowSecurity, hasSubLink);
if (securityQuals != NIL) {
/*
* Add the new security barrier quals to the start of the RTE's
* list so that they get applied before any existing barrier quals
* (which would have come from a security-barrier view, and should
* get lower priority than RLS conditions on the table itself).
*/
if (hasSubLink) {
if (list_member_oid(activeRIRs, rte->relid)) {
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("infinite recursion detected, please check the row level security "
"policies for relation \"%s\"",
RelationGetRelationName(targetTable))));
}
activeRIRs = lcons_oid(rte->relid, activeRIRs);
/*
* Get row level security policies just passed back securityQuals and
* there were SubLink, make sure we lock any relations which are referenced.
* These locks would normally be acquired by the parser, but securityQuals
* are added post-parsing.
*/
(void)acquireLocksOnSubLinks((Node*)securityQuals, NULL);
(void)expression_tree_walker((Node*)securityQuals, (bool (*)())fireRIRonSubLink, (void*)activeRIRs);
activeRIRs = list_delete_first(activeRIRs);
parsetree->hasSubLinks = true;
}
rte->securityQuals = list_concat(securityQuals, rte->securityQuals);
}
/* Update Query hasRowSecurity */
parsetree->hasRowSecurity = (hasRowSecurity || parsetree->hasRowSecurity);
relation_close(targetTable, NoLock);
}
}
return parsetree;
}
/*
* Modify the given query by adding 'AND rule_qual IS NOT TRUE' to its
* qualification. This is used to generate suitable "else clauses" for
* conditional INSTEAD rules. (Unfortunately we must use "x IS NOT TRUE",
* not just "NOT x" which the planner is much smarter about, else we will
* do the wrong thing when the qual evaluates to NULL.)
*
* The rule_qual may contain references to OLD or NEW. OLD references are
* replaced by references to the specified rt_index (the relation that the
* rule applies to). NEW references are only possible for INSERT and UPDATE
* queries on the relation itself, and so they should be replaced by copies
* of the related entries in the query's own targetlist.
*/
static Query* CopyAndAddInvertedQual(Query* parsetree, Node* rule_qual, int rt_index, CmdType event)
{
/* Don't scribble on the passed qual (it's in the relcache!) */
Node* new_qual = (Node*)copyObject(rule_qual);
/*
* In case there are subqueries in the qual, acquire necessary locks and
* fix any deleted JOIN RTE entries. (This is somewhat redundant with
* rewriteRuleAction, but not entirely ... consider restructuring so that
* we only need to process the qual this way once.)
*/
(void)acquireLocksOnSubLinks(new_qual, NULL);
/* Fix references to OLD */
ChangeVarNodes(new_qual, PRS2_OLD_VARNO, rt_index, 0);
/* Fix references to NEW */
if (event == CMD_INSERT || event == CMD_UPDATE)
new_qual = ResolveNew(new_qual,
PRS2_NEW_VARNO,
0,
rt_fetch(rt_index, parsetree->rtable),
parsetree->targetList,
event,
rt_index,
&parsetree->hasSubLinks);
/* And attach the fixed qual */
AddInvertedQual(parsetree, new_qual);
return parsetree;
}
/*
* very same to pg's rewriteTargetListIU. we adapt it to use for MergeInto
*/
static List* rewriteTargetListMergeInto(
List* targetList, CmdType commandType, Relation target_relation, List** attrno_list)
{
TargetEntry** new_tles;
List* new_tlist = NIL;
List* junk_tlist = NIL;
Form_pg_attribute att_tup;
int attrno, next_junk_attrno, numattrs;
ListCell* temp = NULL;
if (attrno_list != NULL) /* initialize optional result list */
*attrno_list = NIL;
/*
* We process the normal (non-junk) attributes by scanning the input tlist
* once and transferring TLEs into an array, then scanning the array to
* build an output tlist. This avoids O(N^2) behavior for large numbers
* of attributes.
*
* Junk attributes are tossed into a separate list during the same tlist
* scan, then appended to the reconstructed tlist.
*/
numattrs = RelationGetNumberOfAttributes(target_relation);
new_tles = (TargetEntry**)palloc0(size_t(numattrs) * sizeof(TargetEntry*));
next_junk_attrno = numattrs + 1;
foreach (temp, targetList) {
TargetEntry* old_tle = (TargetEntry*)lfirst(temp);
if (!old_tle->resjunk) {
/* Normal attr: stash it into new_tles[] */
attrno = old_tle->resno;
if (attrno < 1 || attrno > numattrs) {
ereport(ERROR, (errcode(ERRCODE_AMBIGUOUS_COLUMN), errmsg("bogus resno %d in targetlist", attrno)));
}
att_tup = target_relation->rd_att->attrs[attrno - 1];
/* put attrno into attrno_list even if it's dropped */
if (attrno_list != NULL)
*attrno_list = lappend_int(*attrno_list, attrno);
/* We can (and must) ignore deleted attributes */
if (att_tup->attisdropped)
continue;
/* Merge with any prior assignment to same attribute */
new_tles[attrno - 1] = process_matched_tle(old_tle, new_tles[attrno - 1], NameStr(att_tup->attname));
} else {
/*
* Copy all resjunk tlist entries to junk_tlist, and assign them
* resnos above the last real resno.
*
* Typical junk entries include ORDER BY or GROUP BY expressions
* (are these actually possible in an INSERT or UPDATE?), system
* attribute references, etc.
*/
/* Get the resno right, but don't copy unnecessarily */
if (old_tle->resno != next_junk_attrno) {
old_tle = flatCopyTargetEntry(old_tle);
old_tle->resno = (int16)next_junk_attrno;
}
junk_tlist = lappend(junk_tlist, old_tle);
next_junk_attrno++;
}
}
for (attrno = 1; attrno <= numattrs; attrno++) {
TargetEntry* new_tle = new_tles[attrno - 1];
bool apply_default = false;
att_tup = target_relation->rd_att->attrs[attrno - 1];
/* We can (and must) ignore deleted attributes */
if (att_tup->attisdropped)
continue;
/*
* Handle the two cases where we need to insert a default expression:
* it's an INSERT and there's no tlist entry for the column, or the
* tlist entry is a DEFAULT placeholder node.
*/
apply_default = ((new_tle == NULL && commandType == CMD_INSERT) ||
(new_tle && new_tle->expr && IsA(new_tle->expr, SetToDefault)));
if (apply_default) {
Node* new_expr = NULL;
new_expr = build_column_default(target_relation, attrno, (commandType == CMD_INSERT));
/*
* If there is no default (ie, default is effectively NULL), we
* can omit the tlist entry in the INSERT case, since the planner
* can insert a NULL for itself, and there's no point in spending
* any more rewriter cycles on the entry. But in the UPDATE case
* we've got to explicitly set the column to NULL.
*/
if (new_expr == NULL) {
if (commandType == CMD_INSERT)
new_tle = NULL;
else {
new_expr = (Node*)makeConst(att_tup->atttypid,
-1,
att_tup->attcollation,
att_tup->attlen,
(Datum)0,
true, /* isnull */
att_tup->attbyval);
/* this is to catch a NOT NULL domain constraint */
new_expr = coerce_to_domain(
new_expr, InvalidOid, -1, att_tup->atttypid, COERCE_IMPLICIT_CAST, -1, false, false);
}
}
if (new_expr != NULL)
new_tle = makeTargetEntry((Expr*)new_expr, attrno, pstrdup(NameStr(att_tup->attname)), false);
}
if (new_tle != NULL)
new_tlist = lappend(new_tlist, new_tle);
}
pfree_ext(new_tles);
return list_concat(new_tlist, junk_tlist);
}
/*
* fireRules -
* Iterate through rule locks applying rules.
*
* Input arguments:
* parsetree - original query
* rt_index - RT index of result relation in original query
* event - type of rule event
* locks - list of rules to fire
* Output arguments:
* *instead_flag - set TRUE if any unqualified INSTEAD rule is found
* (must be initialized to FALSE)
* *returning_flag - set TRUE if we rewrite RETURNING clause in any rule
* (must be initialized to FALSE)
* *qual_product - filled with modified original query if any qualified
* INSTEAD rule is found (must be initialized to NULL)
* Return value:
* list of rule actions adjusted for use with this query
*
* Qualified INSTEAD rules generate their action with the qualification
* condition added. They also generate a modified version of the original
* query with the negated qualification added, so that it will run only for
* rows that the qualified action doesn't act on. (If there are multiple
* qualified INSTEAD rules, we AND all the negated quals onto a single
* modified original query.) We won't execute the original, unmodified
* query if we find either qualified or unqualified INSTEAD rules. If
* we find both, the modified original query is discarded too.
*/
static List* fireRules(Query* parsetree, int rt_index, CmdType event, List* locks, bool* instead_flag,
bool* returning_flag, Query** qual_product)
{
List* results = NIL;
ListCell* l = NULL;
foreach (l, locks) {
RewriteRule* rule_lock = (RewriteRule*)lfirst(l);
Node* event_qual = rule_lock->qual;
List* actions = rule_lock->actions;
QuerySource qsrc;
ListCell* r = NULL;
/* Determine correct QuerySource value for actions */
if (rule_lock->isInstead) {
if (event_qual != NULL)
qsrc = QSRC_QUAL_INSTEAD_RULE;
else {
qsrc = QSRC_INSTEAD_RULE;
*instead_flag = true; /* report unqualified INSTEAD */
}
} else
qsrc = QSRC_NON_INSTEAD_RULE;
if (qsrc == QSRC_QUAL_INSTEAD_RULE) {
/*
* If there are INSTEAD rules with qualifications, the original
* query is still performed. But all the negated rule
* qualifications of the INSTEAD rules are added so it does its
* actions only in cases where the rule quals of all INSTEAD rules
* are false. Think of it as the default action in a case. We save
* this in *qual_product so RewriteQuery() can add it to the query
* list after we mangled it up enough.
*
* If we have already found an unqualified INSTEAD rule, then
* *qual_product won't be used, so don't bother building it.
*/
if (!*instead_flag) {
if (*qual_product == NULL)
*qual_product = (Query*)copyObject(parsetree);
*qual_product = CopyAndAddInvertedQual(*qual_product, event_qual, rt_index, event);
}
}
/* Now process the rule's actions and add them to the result list */
foreach (r, actions) {
Query* rule_action = (Query*)lfirst(r);
if (rule_action->commandType == CMD_NOTHING)
continue;
rule_action = rewriteRuleAction(parsetree, rule_action, event_qual, rt_index, event, returning_flag);
rule_action->querySource = qsrc;
rule_action->canSetTag = false; /* might change later */
results = lappend(results, rule_action);
}
}
return results;
}
void ereport_for_each_cmdtype(CmdType event, Relation rt_entry_relation)
{
switch (event) {
case CMD_INSERT:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot perform INSERT RETURNING on relation \"%s\"",
RelationGetRelationName(rt_entry_relation)),
errhint("You need an unconditional ON INSERT DO INSTEAD rule with a RETURNING clause.")));
break;
case CMD_UPDATE:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot perform UPDATE RETURNING on relation \"%s\"",
RelationGetRelationName(rt_entry_relation)),
errhint("You need an unconditional ON UPDATE DO INSTEAD rule with a RETURNING clause.")));
break;
case CMD_DELETE:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot perform DELETE RETURNING on relation \"%s\"",
RelationGetRelationName(rt_entry_relation)),
errhint("You need an unconditional ON DELETE DO INSTEAD rule with a RETURNING clause.")));
break;
default: {
ereport(
ERROR, (errcode(ERRCODE_UNEXPECTED_NODE_STATE), errmsg("unrecognized commandType: %d", (int)event)));
} break;
}
}
/*
* RewriteQuery -
* rewrites the query and apply the rules again on the queries rewritten
*
* rewrite_events is a list of open query-rewrite actions, so we can detect
* infinite recursion.
*/
static List* RewriteQuery(Query* parsetree, List* rewrite_events)
{
CmdType event = parsetree->commandType;
bool instead = false;
bool returning = false;
Query* qual_product = NULL;
List* rewritten = NIL;
ListCell* lc1 = NULL;
#ifdef PGXC
List* parsetree_list = NIL;
List* qual_product_list = NIL;
ListCell* pt_cell = NULL;
#endif
/*
* First, recursively process any insert/update/delete statements in WITH
* clauses. (We have to do this first because the WITH clauses may get
* copied into rule actions below.)
*/
foreach (lc1, parsetree->cteList) {
CommonTableExpr* cte = (CommonTableExpr*)lfirst(lc1);
Query* ctequery = (Query*)cte->ctequery;
List* newstuff = NIL;
AssertEreport(IsA(ctequery, Query), MOD_OPT, "");
if (ctequery->commandType == CMD_SELECT)
continue;
newstuff = RewriteQuery(ctequery, rewrite_events);
/*
* Currently we can only handle unconditional, single-statement DO
* INSTEAD rules correctly; we have to get exactly one Query out of
* the rewrite operation to stuff back into the CTE node.
*/
if (list_length(newstuff) == 1) {
/* Push the single Query back into the CTE node */
ctequery = (Query*)linitial(newstuff);
AssertEreport(IsA(ctequery, Query), MOD_OPT, "");
/* WITH queries should never be canSetTag */
AssertEreport(!ctequery->canSetTag, MOD_OPT, "");
cte->ctequery = (Node*)ctequery;
} else if (newstuff == NIL) {
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("DO INSTEAD NOTHING rules are not supported for data-modifying statements in WITH")));
} else {
ListCell* lc2 = NULL;
/* examine queries to determine which error message to issue */
foreach (lc2, newstuff) {
Query* q = (Query*)lfirst(lc2);
if (q->querySource == QSRC_QUAL_INSTEAD_RULE)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("conditional DO INSTEAD rules are not supported for data-modifying statements in "
"WITH")));
if (q->querySource == QSRC_NON_INSTEAD_RULE)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("DO ALSO rules are not supported for data-modifying statements in WITH")));
}
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg(
"multi-statement DO INSTEAD rules are not supported for data-modifying statements in WITH")));
}
}
/*
* If the statement is an insert, update, or delete, adjust its targetlist
* as needed, and then fire INSERT/UPDATE/DELETE rules on it.
*
* SELECT rules are handled later when we have all the queries that should
* get executed. Also, utilities aren't rewritten at all (do we still
* need that check?)
*/
if (event != CMD_SELECT && event != CMD_UTILITY) {
int result_relation;
RangeTblEntry* rt_entry = NULL;
Relation rt_entry_relation;
List* locks = NIL;
result_relation = parsetree->resultRelation;
if (result_relation == 0)
return rewritten;
rt_entry = rt_fetch(result_relation, parsetree->rtable);
AssertEreport(rt_entry->rtekind == RTE_RELATION, MOD_OPT, "");
/*
* We can use NoLock here since either the parser or
* AcquireRewriteLocks should have locked the rel already.
*/
rt_entry_relation = heap_open(rt_entry->relid, NoLock);
/*
* Rewrite the targetlist as needed for the command type.
*/
if (event == CMD_INSERT) {
RangeTblEntry* values_rte = NULL;
/*
* If it's an INSERT ... VALUES (...), (...), ... there will be a
* single RTE for the VALUES targetlists.
*/
if (list_length(parsetree->jointree->fromlist) == 1) {
RangeTblRef* rtr = (RangeTblRef*)linitial(parsetree->jointree->fromlist);
if (IsA(rtr, RangeTblRef)) {
RangeTblEntry* rte = rt_fetch(rtr->rtindex, parsetree->rtable);
if (rte->rtekind == RTE_VALUES)
values_rte = rte;
}
}
if (values_rte != NULL) {
List* attrnos = NIL;
/* Process the main targetlist ... */
parsetree->targetList =
rewriteTargetListIU(parsetree->targetList, parsetree->commandType,
rt_entry_relation, parsetree->resultRelation, &attrnos);
/* ... and the VALUES expression lists */
rewriteValuesRTE(values_rte, rt_entry_relation, attrnos);
} else {
/* Process just the main targetlist */
parsetree->targetList =
rewriteTargetListIU(parsetree->targetList, parsetree->commandType,
rt_entry_relation, parsetree->resultRelation, NULL);
}
if (parsetree->upsertClause != NULL &&
parsetree->upsertClause->upsertAction == UPSERT_UPDATE) {
parsetree->upsertClause->updateTlist =
rewriteTargetListIU(parsetree->upsertClause->updateTlist, CMD_UPDATE,
rt_entry_relation, parsetree->resultRelation, NULL);
}
} else if (event == CMD_UPDATE) {
parsetree->targetList =
rewriteTargetListIU(parsetree->targetList, parsetree->commandType,
rt_entry_relation, parsetree->resultRelation, NULL);
rewriteTargetListUD(parsetree, rt_entry, rt_entry_relation);
} else if (event == CMD_MERGE) {
/*
* Rewrite each action targetlist separately
*/
foreach (lc1, parsetree->mergeActionList) {
MergeAction* action = (MergeAction*)lfirst(lc1);
switch (action->commandType) {
case CMD_DELETE: /* Nothing to do here */
break;
case CMD_UPDATE:
action->targetList = rewriteTargetListMergeInto(action->targetList,
action->commandType,
rt_entry_relation,
NULL);
break;
case CMD_INSERT: {
action->targetList = rewriteTargetListMergeInto(action->targetList,
action->commandType,
rt_entry_relation,
NULL);
} break;
default: {
ereport(ERROR,
(errcode(ERRCODE_UNEXPECTED_NODE_STATE),
errmsg("unrecognized commandType: %d", action->commandType)));
} break;
}
}
} else if (event == CMD_DELETE) {
rewriteTargetListUD(parsetree, rt_entry, rt_entry_relation);
} else {
ereport(ERROR, (errcode(ERRCODE_INVALID_OPERATION), errmsg("unrecognized commandType: %d", (int)event)));
}
#ifdef PGXC
if (parsetree_list == NIL) {
#endif
/*
* Collect and apply the appropriate rules.
*/
locks = matchLocks(event, rt_entry_relation->rd_rules, result_relation, parsetree);
if (locks != NIL) {
#ifdef PGXC
List* product_queries = NIL;
if (IS_SINGLE_NODE || IS_PGXC_COORDINATOR)
#else
List* product_queries;
#endif
product_queries =
fireRules(parsetree, result_relation, event, locks, &instead, &returning, &qual_product);
/*
* If we got any product queries, recursively rewrite them --- but
* first check for recursion!
*/
if (product_queries != NIL) {
ListCell* n = NULL;
rewrite_event* rev = NULL;
foreach (n, rewrite_events) {
rev = (rewrite_event*)lfirst(n);
if (rev->relation == RelationGetRelid(rt_entry_relation) && rev->event == event)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("infinite recursion detected in rules for relation \"%s\"",
RelationGetRelationName(rt_entry_relation))));
}
rev = (rewrite_event*)palloc(sizeof(rewrite_event));
rev->relation = RelationGetRelid(rt_entry_relation);
rev->event = event;
rewrite_events = lcons(rev, rewrite_events);
foreach (n, product_queries) {
Query* pt = (Query*)lfirst(n);
List* newstuff = NULL;
newstuff = RewriteQuery(pt, rewrite_events);
rewritten = list_concat(rewritten, newstuff);
}
rewrite_events = list_delete_first(rewrite_events);
}
}
/*
* If there is an INSTEAD, and the original query has a RETURNING, we
* have to have found a RETURNING in the rule(s), else fail. (Because
* DefineQueryRewrite only allows RETURNING in unconditional INSTEAD
* rules, there's no need to worry whether the substituted RETURNING
* will actually be executed --- it must be.)
*/
if ((instead || qual_product != NULL) && parsetree->returningList && !returning) {
ereport_for_each_cmdtype(event, rt_entry_relation);
}
heap_close(rt_entry_relation, NoLock);
#ifdef PGXC
} else {
foreach (pt_cell, parsetree_list) {
Query* query = NULL;
query = (Query*)lfirst(pt_cell);
/*
* Collect and apply the appropriate rules.
*/
locks = matchLocks(event, rt_entry_relation->rd_rules, result_relation, query);
if (locks != NIL) {
List* product_queries = NIL;
if (IS_PGXC_COORDINATOR)
product_queries =
fireRules(query, result_relation, event, locks, &instead, &returning, &qual_product);
qual_product_list = lappend(qual_product_list, qual_product);
/*
* If we got any product queries, recursively rewrite them --- but
* first check for recursion!
*/
if (product_queries != NIL) {
ListCell* n = NULL;
rewrite_event* rev = NULL;
foreach (n, rewrite_events) {
rev = (rewrite_event*)lfirst(n);
if (rev->relation == RelationGetRelid(rt_entry_relation) && rev->event == event)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("infinite recursion detected in rules for relation \"%s\"",
RelationGetRelationName(rt_entry_relation))));
}
rev = (rewrite_event*)palloc(sizeof(rewrite_event));
rev->relation = RelationGetRelid(rt_entry_relation);
rev->event = event;
rewrite_events = lcons(rev, rewrite_events);
foreach (n, product_queries) {
Query* pt = (Query*)lfirst(n);
List* newstuff = NIL;
newstuff = RewriteQuery(pt, rewrite_events);
rewritten = list_concat(rewritten, newstuff);
}
rewrite_events = list_delete_first(rewrite_events);
}
}
/*
* If there is an INSTEAD, and the original query has a RETURNING, we
* have to have found a RETURNING in the rule(s), else fail. (Because
* DefineQueryRewrite only allows RETURNING in unconditional INSTEAD
* rules, there's no need to worry whether the substituted RETURNING
* will actually be executed --- it must be.)
*/
if ((instead || qual_product != NULL) && query->returningList && !returning) {
ereport_for_each_cmdtype(event, rt_entry_relation);
}
}
heap_close(rt_entry_relation, NoLock);
}
}
if (parsetree_list == NIL) {
#endif
/*
* For INSERTs, the original query is done first; for UPDATE/DELETE, it is
* done last. This is needed because update and delete rule actions might
* not do anything if they are invoked after the update or delete is
* performed. The command counter increment between the query executions
* makes the deleted (and maybe the updated) tuples disappear so the scans
* for them in the rule actions cannot find them.
*
* If we found any unqualified INSTEAD, the original query is not done at
* all, in any form. Otherwise, we add the modified form if qualified
* INSTEADs were found, else the unmodified form.
*/
if (!instead) {
if (parsetree->commandType == CMD_INSERT) {
if (qual_product != NULL)
rewritten = lcons(qual_product, rewritten);
else
rewritten = lcons(parsetree, rewritten);
} else {
if (qual_product != NULL)
rewritten = lappend(rewritten, qual_product);
else
rewritten = lappend(rewritten, parsetree);
}
}
#ifdef PGXC
} else {
int query_no = 0;
foreach (pt_cell, parsetree_list) {
Query* query = NULL;
Query* qual = NULL;
query = (Query*)lfirst(pt_cell);
if (instead == false) {
if (qual_product_list != NIL)
qual = (Query*)list_nth(qual_product_list, query_no);
if (query->commandType == CMD_INSERT) {
if (qual != NULL)
rewritten = lcons(qual, rewritten);
else
rewritten = lcons(query, rewritten);
} else {
if (qual != NULL)
rewritten = lappend(rewritten, qual);
else
rewritten = lappend(rewritten, query);
}
}
query_no++;
}
}
#endif
/*
* If the original query has a CTE list, and we generated more than one
* non-utility result query, we have to fail because we'll have copied the
* CTE list into each result query. That would break the expectation of
* single evaluation of CTEs. This could possibly be fixed by
* restructuring so that a CTE list can be shared across multiple Query
* and PlannableStatement nodes.
*/
if (parsetree->cteList != NIL) {
int qcount = 0;
foreach (lc1, rewritten) {
Query* q = (Query*)lfirst(lc1);
if (q->commandType != CMD_UTILITY)
qcount++;
}
if (qcount > 1)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("WITH cannot be used in a query that is rewritten by rules into multiple queries")));
}
return rewritten;
}
/*
* QueryRewrite -
* Primary entry point to the query rewriter.
* Rewrite one query via query rewrite system, possibly returning 0
* or many queries.
*
* NOTE: the parsetree must either have come straight from the parser,
* or have been scanned by AcquireRewriteLocks to acquire suitable locks.
*/
List* QueryRewrite(Query* parsetree)
{
uint64 input_query_id = parsetree->queryId;
List* querylist = NIL;
List* results = NIL;
ListCell* l = NULL;
CmdType origCmdType;
bool foundOriginalQuery = false;
Query* lastInstead = NULL;
/*
* This function is only applied to top-level original queries
*/
AssertEreport(parsetree->querySource == QSRC_ORIGINAL, MOD_OPT, "");
AssertEreport(parsetree->canSetTag, MOD_OPT, "");
/*
* Step 1
*
* Apply all non-SELECT rules possibly getting 0 or many queries
*/
querylist = RewriteQuery(parsetree, NIL);
/*
* Step 2
*
* Apply all the RIR rules on each query
*
* This is also a handy place to mark each query with the original queryId
*/
results = NIL;
foreach (l, querylist) {
Query* query = (Query*)lfirst(l);
query = fireRIRrules(query, NIL, false);
query->queryId = input_query_id;
results = lappend(results, query);
}
/*
* Step 3
*
* Determine which, if any, of the resulting queries is supposed to set
* the command-result tag; and update the canSetTag fields accordingly.
*
* If the original query is still in the list, it sets the command tag.
* Otherwise, the last INSTEAD query of the same kind as the original is
* allowed to set the tag. (Note these rules can leave us with no query
* setting the tag. The tcop code has to cope with this by setting up a
* default tag based on the original un-rewritten query.)
*
* The Asserts verify that at most one query in the result list is marked
* canSetTag. If we aren't checking asserts, we can fall out of the loop
* as soon as we find the original query.
*/
origCmdType = parsetree->commandType;
foundOriginalQuery = false;
lastInstead = NULL;
foreach (l, results) {
Query* query = (Query*)lfirst(l);
if (query->querySource == QSRC_ORIGINAL) {
AssertEreport(query->canSetTag, MOD_OPT, "");
#ifndef PGXC
AssertEreport(!foundOriginalQuery, MOD_OPT, "");
#endif
foundOriginalQuery = true;
#ifndef USE_ASSERT_CHECKING
break;
#endif
} else {
AssertEreport(!query->canSetTag, MOD_OPT, "");
if (query->commandType == origCmdType &&
(query->querySource == QSRC_INSTEAD_RULE || query->querySource == QSRC_QUAL_INSTEAD_RULE))
lastInstead = query;
}
}
if (!foundOriginalQuery && lastInstead != NULL)
lastInstead->canSetTag = true;
if (CONVERT_STRING_DIGIT_TO_NUMERIC) {
foreach (l, results) {
(void)PreprocessOperator((Node*)lfirst(l), NULL);
}
}
return results;
}
#ifdef PGXC
/*
* Rewrite the CREATE TABLE AS and SELECT INTO queries as a
* INSERT INTO .. SELECT query. The target table must be created first using
* utility command processing. This takes care of creating the target table on
* all the Coordinators and the Datanodes.
*/
List* QueryRewriteCTAS(Query* parsetree)
{
RangeVar* relation = NULL;
CreateStmt* create_stmt = NULL;
List* tableElts = NIL;
StringInfoData cquery;
ListCell* col = NULL;
Query* cparsetree = NULL;
List* raw_parsetree_list = NIL;
List* tlist = NIL;
char* selectstr = NULL;
CreateTableAsStmt* stmt = NULL;
IntoClause* into = NULL;
ListCell* lc = NULL;
if (parsetree->commandType != CMD_UTILITY || !IsA(parsetree->utilityStmt, CreateTableAsStmt)) {
ereport(ERROR,
(errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
errmsg("Unexpected commandType or intoClause is not set properly")));
}
/* Get the target table */
stmt = (CreateTableAsStmt*)parsetree->utilityStmt;
relation = stmt->into->rel;
if (!t_thrd.postgres_cxt.table_created_in_CTAS) {
/* Start building a CreateStmt for creating the target table */
create_stmt = makeNode(CreateStmt);
create_stmt->relation = relation;
into = stmt->into;
/* Obtain the target list of new table */
AssertEreport(IsA(stmt->query, Query), MOD_OPT, "");
cparsetree = (Query*)stmt->query;
tlist = cparsetree->targetList;
/*
* Based on the targetList, populate the column information for the target
* table. If a column name list was specified in CREATE TABLE AS, override
* the column names derived from the query. (Too few column names are OK, too
* many are not.).
*/
lc = list_head(into->colNames);
foreach (col, tlist) {
TargetEntry* tle = (TargetEntry*)lfirst(col);
ColumnDef* coldef = NULL;
TypeName* tpname = NULL;
if (IsA(tle->expr, Var)) {
Var* ColTypProperty = (Var*)(tle->expr);
/*
* It's possible that the column is of a collatable type but the
* collation could not be resolved, so double-check. (We must check
* this here because DefineRelation would adopt the type's default
* collation rather than complaining.)
*/
if (!OidIsValid(ColTypProperty->varcollid) && type_is_collatable(ColTypProperty->vartype))
ereport(ERROR,
(errcode(ERRCODE_INDETERMINATE_COLLATION),
errmsg("no collation was derived for column \"%s\" with collatable type %s",
tle->resname,
format_type_be(ColTypProperty->vartype)),
errhint("Use the COLLATE clause to set the collation explicitly.")));
}
/* Ignore junk columns from the targetlist */
if (tle->resjunk)
continue;
coldef = makeNode(ColumnDef);
tpname = makeNode(TypeName);
/* Take the column name specified if any */
if (lc != NULL) {
coldef->colname = strVal(lfirst(lc));
lc = lnext(lc);
} else
coldef->colname = pstrdup(tle->resname);
coldef->inhcount = 0;
coldef->is_local = true;
coldef->is_not_null = false;
/* The best way to set cmprs_mode is copied from the source column defination.
* but the cost is heavy, so make it the default method without forbiting compressing.
* refer to ExecCreateTableAs() --> CreateIntoRelDestReceiver() --> intorel_startup()
*/
coldef->cmprs_mode = ATT_CMPR_UNDEFINED;
coldef->raw_default = NULL;
coldef->cooked_default = NULL;
coldef->constraints = NIL;
/*
* Set typeOid and typemod. The name of the type is derived while
* generating query
*/
tpname->typeOid = exprType((Node*)tle->expr);
tpname->typemod = exprTypmod((Node*)tle->expr);
coldef->typname = tpname;
tableElts = lappend(tableElts, coldef);
}
if (lc != NULL)
ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("CREATE TABLE AS specifies too many column names")));
/*
* Set column information and the distribution mechanism (which will be
* NULL for SELECT INTO and the default mechanism will be picked)
*/
create_stmt->tableElts = tableElts;
create_stmt->distributeby = stmt->into->distributeby;
create_stmt->subcluster = stmt->into->subcluster;
create_stmt->tablespacename = stmt->into->tableSpaceName;
create_stmt->oncommit = stmt->into->onCommit;
create_stmt->row_compress = stmt->into->row_compress;
create_stmt->options = stmt->into->options;
/*
* Check consistency of arguments
*/
if (create_stmt->oncommit != ONCOMMIT_NOOP &&
(create_stmt->relation->relpersistence != RELPERSISTENCE_TEMP &&
create_stmt->relation->relpersistence != RELPERSISTENCE_GLOBAL_TEMP))
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("ON COMMIT can only be used on temporary tables")));
/* Get a copy of the parsetree which we can freely modify */
cparsetree = (Query*)copyObject(parsetree);
/*
* Now build a utility statement in order to run the CREATE TABLE DDL on
* the local and remote nodes. We keep others fields as it is since they
* are ignored anyways by deparse_query.
*/
cparsetree->commandType = CMD_UTILITY;
cparsetree->utilityStmt = (Node*)create_stmt;
initStringInfo(&cquery);
deparse_query(cparsetree, &cquery, NIL, false, false);
/* Finally, fire off the query to run the DDL */
ProcessUtility(cparsetree->utilityStmt, cquery.data, NULL, true, NULL, false, NULL);
/*
* Now fold the CTAS statement into an INSERT INTO statement. The
* utility is no more required.
*/
parsetree->utilityStmt = NULL;
}
/* Get the SELECT query string */
/*
* If target table name is the same as an existed one and schema name is NULL, INSERT INTO
* statement may not find the right target table. Therefore we should get the schema name
* first so that the INSERT INTO statement can insert into the target table.
*/
if (relation->schemaname == NULL && relation->relpersistence != RELPERSISTENCE_TEMP) {
Oid namespaceid = RangeVarGetAndCheckCreationNamespace(relation, NoLock, NULL);
relation->schemaname = get_namespace_name(namespaceid, true);
}
initStringInfo(&cquery);
deparse_query((Query*)stmt->query, &cquery, NIL, false, false, stmt->parserSetupArg);
selectstr = pstrdup(cquery.data);
/* Now, finally build the INSERT INTO statement */
initStringInfo(&cquery);
if (relation->schemaname)
appendStringInfo(
&cquery, "INSERT INTO %s.%s", quote_identifier(relation->schemaname), quote_identifier(relation->relname));
else
appendStringInfo(&cquery, "INSERT INTO %s", quote_identifier(relation->relname));
/*
* If the original sql contains "WITH NO DATA", just create
* the table without inserting any data.
*/
if (stmt->into->skipData)
appendStringInfoString(&cquery, " select null where false");
else
appendStringInfo(&cquery, " %s", selectstr);
raw_parsetree_list = pg_parse_query(cquery.data);
if (stmt->parserSetup != NULL) {
return pg_analyze_and_rewrite_params(
(Node*)linitial(raw_parsetree_list), cquery.data, (ParserSetupHook)stmt->parserSetup, stmt->parserSetupArg);
} else {
if (strchr(cquery.data, '$') == NULL) {
return pg_analyze_and_rewrite((Node*)linitial(raw_parsetree_list), cquery.data, NULL, 0);
} else {
/* For plpy CTAS with $1, $2... */
return pg_analyze_and_rewrite((Node*)linitial(raw_parsetree_list),
cquery.data,
parsetree->fixed_paramTypes,
parsetree->fixed_numParams);
}
}
}
#endif