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select_into_varlist

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This commit is contained in:
weiwt
2022-11-29 23:40:06 +08:00
parent 7b18154c8d
commit 8274c4041d
26 changed files with 1091 additions and 94 deletions
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54
src/gausskernel/optimizer/util/clauses.cpp
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@ -46,6 +46,7 @@
#include "parser/parse_agg.h"
#include "parser/parse_coerce.h"
#include "parser/parse_func.h"
#include "parser/parsetree.h"
#include "pgxc/pgxc.h"
#include "rewrite/rewriteManip.h"
#include "tcop/tcopprot.h"
@ -2400,6 +2401,59 @@ Node* estimate_expression_value(PlannerInfo* root, Node* node, EState* estate)
return eval_const_expressions_mutator(node, &context);
}
/* --------------------
* simplify_subselect_expression
*
* Only for select ... into varlist statement.
*
* This function attempts to bind the value of parameter
* in the part of Select part without into_clause
* for the following process to calculate the value.
* --------------------
*/
Node* simplify_subselect_expression(Node* node, ParamListInfo boundParams)
{
eval_const_expressions_context context;
context.boundParams = boundParams;
context.root = NULL; /* for inlined-function dependencies */
context.active_fns = NIL; /* nothing being recursively simplified */
context.case_val = NULL; /* no CASE being examined */
context.estimate = true; /* unsafe transformations OK */
Query *qt = (Query *)((SubLink *)node)->subselect;
List *fromList = qt->jointree->fromlist;
ListCell *fc = NULL;
foreach (fc, fromList) {
Node *jtnode = (Node *)lfirst(fc);
if (IsA(jtnode, RangeTblRef)) {
int varno = ((RangeTblRef *)jtnode)->rtindex;
RangeTblEntry *rte = rt_fetch(varno, qt->rtable);
if (rte->funcexpr != NULL && IsA(rte->funcexpr, FuncExpr)) {
rte->funcexpr = eval_const_expressions_mutator((Node *)rte->funcexpr, &context);
}
}
}
ListCell *lc = NULL;
AttrNumber attno = 1;
List *newTargetList = NIL;
foreach (lc, qt->targetList) {
TargetEntry *te = (TargetEntry *)lfirst(lc);
Node *tn = (Node *)te->expr;
if(IsA(tn, Param) || IsA(tn, OpExpr)) {
tn = eval_const_expressions_mutator(tn, &context);
te = makeTargetEntry((Expr *)tn, attno++, te->resname, false);
newTargetList = lappend(newTargetList, te);
}
}
if (newTargetList != NIL) {
qt->targetList = newTargetList;
}
return node;
}
Node* eval_const_expressions_mutator(Node* node, eval_const_expressions_context* context)
{
if (node == NULL)