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Further tweaking of parsetree & plantree representation of SubLinks.

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Simplify SubLink by storing just a List of operator OIDs, instead of
a list of incomplete OpExprs --- that was a bizarre and bulky choice,
with no redeeming social value since we have to build new OpExprs
anyway when forming the plan tree.
This commit is contained in:
Tom Lane
2003-01-10 21:08:15 +00:00
parent 36ea26793a
commit e69785debf
17 changed files with 407 additions and 246 deletions
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43
src/backend/parser/parse_expr.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.139 2003/01/09 20:50:52 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.140 2003/01/10 21:08:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -366,8 +366,8 @@ transformExpr(ParseState *pstate, Node *expr)
* These fields should be NIL already, but make sure.
*/
sublink->lefthand = NIL;
sublink->oper = NIL;
sublink->operIsEquals = FALSE;
sublink->operName = NIL;
sublink->operOids = NIL;
sublink->useOr = FALSE;
}
else if (sublink->subLinkType == EXPR_SUBLINK)
@ -392,8 +392,8 @@ transformExpr(ParseState *pstate, Node *expr)
* fields should be NIL already, but make sure.
*/
sublink->lefthand = NIL;
sublink->oper = NIL;
sublink->operIsEquals = FALSE;
sublink->operName = NIL;
sublink->operOids = NIL;
sublink->useOr = FALSE;
}
else
@ -403,20 +403,14 @@ transformExpr(ParseState *pstate, Node *expr)
List *right_list = qtree->targetList;
int row_length = length(left_list);
bool needNot = false;
List *op;
char *opname;
List *op = sublink->operName;
char *opname = strVal(llast(op));
List *elist;
/* transform lefthand expressions */
foreach(elist, left_list)
lfirst(elist) = transformExpr(pstate, lfirst(elist));
/* get the combining-operator name */
Assert(IsA(sublink->oper, A_Expr));
op = ((A_Expr *) sublink->oper)->name;
opname = strVal(llast(op));
sublink->oper = NIL;
/*
* If the expression is "<> ALL" (with unqualified opname)
* then convert it to "NOT IN". This is a hack to improve
@ -428,15 +422,10 @@ transformExpr(ParseState *pstate, Node *expr)
sublink->subLinkType = ANY_SUBLINK;
opname = pstrdup("=");
op = makeList1(makeString(opname));
sublink->operName = op;
needNot = true;
}
/* Set operIsEquals if op is unqualified "=" */
if (length(op) == 1 && strcmp(opname, "=") == 0)
sublink->operIsEquals = TRUE;
else
sublink->operIsEquals = FALSE;
/* Set useOr if op is "<>" (possibly qualified) */
if (strcmp(opname, "<>") == 0)
sublink->useOr = TRUE;
@ -451,19 +440,21 @@ transformExpr(ParseState *pstate, Node *expr)
opname);
/*
* Scan subquery's targetlist to find values that will
* To build the list of combining operator OIDs, we must
* scan subquery's targetlist to find values that will
* be matched against lefthand values. We need to
* ignore resjunk targets, so doing the outer
* iteration over right_list is easier than doing it
* over left_list.
*/
sublink->operOids = NIL;
while (right_list != NIL)
{
TargetEntry *tent = (TargetEntry *) lfirst(right_list);
Node *lexpr;
Operator optup;
Form_pg_operator opform;
OpExpr *newop;
right_list = lnext(right_list);
if (tent->resdom->resjunk)
@ -496,14 +487,8 @@ transformExpr(ParseState *pstate, Node *expr)
" to be used with quantified predicate subquery",
opname);
newop = makeNode(OpExpr);
newop->opno = oprid(optup);
newop->opfuncid = InvalidOid;
newop->opresulttype = opform->oprresult;
newop->opretset = false;
newop->args = NIL; /* for now */
sublink->oper = lappend(sublink->oper, newop);
sublink->operOids = lappendi(sublink->operOids,
oprid(optup));
ReleaseSysCache(optup);
}