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Replace rewriter's checkQueryHasAggs and checkQueryHasSubLink

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with expression_tree_walker-based code.  The former failed to cope with
expressions containing SubLinks, and the latter returned TRUE for both
SubLinks and Aggrefs (cut-and-paste bug?).  There is a lot more scope for
using expression_tree_walker in this module, but I'll restrain myself
until the 6.6 split occurs from touching not-demonstrably-broken code.
This commit is contained in:
Tom Lane 1999-06-21 01:26:56 +00:00
parent fd8e580bb7
commit 1f2c6f4f48
1 changed files with 29 additions and 226 deletions
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255
src/backend/rewrite/rewriteHandler.c
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@ -6,7 +6,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.46 1999/05/26 12:55:46 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.47 1999/06/21 01:26:56 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -29,6 +29,7 @@
#include "parser/parse_target.h"
#include "parser/analyze.h"
#include "optimizer/clauses.h"
#include "optimizer/prep.h"
#include "rewrite/rewriteSupport.h"
@ -60,6 +61,9 @@ static void modifyAggrefDropQual(Node **nodePtr, Node *orignode, Expr *expr);
static SubLink *modifyAggrefMakeSublink(Expr *origexp, Query *parsetree);
static void modifyAggrefQual(Node **nodePtr, Query *parsetree);
static bool checkQueryHasAggs(Node *node);
static bool checkQueryHasAggs_walker(Node *node, void *context);
static bool checkQueryHasSubLink(Node *node);
static bool checkQueryHasSubLink_walker(Node *node, void *context);
static Query *fireRIRrules(Query *parsetree);
static Query *Except_Intersect_Rewrite(Query *parsetree);
static void check_targetlists_are_compatible(List *prev_target,
@ -1302,242 +1306,41 @@ modifyAggrefQual(Node **nodePtr, Query *parsetree)
static bool
checkQueryHasAggs(Node *node)
{
if (node == NULL)
return FALSE;
switch (nodeTag(node))
{
case T_TargetEntry:
{
TargetEntry *tle = (TargetEntry *) node;
return checkQueryHasAggs((Node *) (tle->expr));
}
break;
case T_Aggref:
return TRUE;
case T_Expr:
{
Expr *exp = (Expr *) node;
return checkQueryHasAggs((Node *) (exp->args));
}
break;
case T_Iter:
{
Iter *iter = (Iter *) node;
return checkQueryHasAggs((Node *) (iter->iterexpr));
}
break;
case T_ArrayRef:
{
ArrayRef *ref = (ArrayRef *) node;
if (checkQueryHasAggs((Node *) (ref->refupperindexpr)))
return TRUE;
if (checkQueryHasAggs((Node *) (ref->reflowerindexpr)))
return TRUE;
if (checkQueryHasAggs((Node *) (ref->refexpr)))
return TRUE;
if (checkQueryHasAggs((Node *) (ref->refassgnexpr)))
return TRUE;
return FALSE;
}
break;
case T_Var:
return FALSE;
case T_Param:
return FALSE;
case T_Const:
return FALSE;
case T_List:
{
List *l;
foreach(l, (List *) node)
{
if (checkQueryHasAggs((Node *) lfirst(l)))
return TRUE;
}
return FALSE;
}
break;
case T_CaseExpr:
{
CaseExpr *exp = (CaseExpr *) node;
if (checkQueryHasAggs((Node *) (exp->args)))
return TRUE;
if (checkQueryHasAggs((Node *) (exp->defresult)))
return TRUE;
return FALSE;
}
break;
case T_CaseWhen:
{
CaseWhen *when = (CaseWhen *) node;
if (checkQueryHasAggs((Node *) (when->expr)))
return TRUE;
if (checkQueryHasAggs((Node *) (when->result)))
return TRUE;
return FALSE;
}
break;
default:
elog(NOTICE, "unknown node tag %d in checkQueryHasAggs()", nodeTag(node));
elog(NOTICE, "Node is: %s", nodeToString(node));
break;
}
return FALSE;
return checkQueryHasAggs_walker(node, NULL);
}
static bool
checkQueryHasAggs_walker(Node *node, void *context)
{
if (node == NULL)
return false;
if (IsA(node, Aggref))
return true; /* abort the tree traversal and return true */
return expression_tree_walker(node, checkQueryHasAggs_walker, context);
}
/*
* checkQueryHasSubLink -
* Queries marked hasAggs might not have them any longer after
* Queries marked hasSubLinks might not have them any longer after
* rewriting. Check it.
*/
static bool
checkQueryHasSubLink(Node *node)
{
return checkQueryHasSubLink_walker(node, NULL);
}
static bool
checkQueryHasSubLink_walker(Node *node, void *context)
{
if (node == NULL)
return FALSE;
switch (nodeTag(node))
{
case T_TargetEntry:
{
TargetEntry *tle = (TargetEntry *) node;
return checkQueryHasSubLink((Node *) (tle->expr));
}
break;
case T_Aggref:
return TRUE;
case T_Expr:
{
Expr *exp = (Expr *) node;
return checkQueryHasSubLink((Node *) (exp->args));
}
break;
case T_Iter:
{
Iter *iter = (Iter *) node;
return checkQueryHasSubLink((Node *) (iter->iterexpr));
}
break;
case T_ArrayRef:
{
ArrayRef *ref = (ArrayRef *) node;
if (checkQueryHasSubLink((Node *) (ref->refupperindexpr)))
return TRUE;
if (checkQueryHasSubLink((Node *) (ref->reflowerindexpr)))
return TRUE;
if (checkQueryHasSubLink((Node *) (ref->refexpr)))
return TRUE;
if (checkQueryHasSubLink((Node *) (ref->refassgnexpr)))
return TRUE;
return FALSE;
}
break;
case T_Var:
return FALSE;
case T_Param:
return FALSE;
case T_Const:
return FALSE;
case T_List:
{
List *l;
foreach(l, (List *) node)
{
if (checkQueryHasSubLink((Node *) lfirst(l)))
return TRUE;
}
return FALSE;
}
break;
case T_CaseExpr:
{
CaseExpr *exp = (CaseExpr *) node;
if (checkQueryHasSubLink((Node *) (exp->args)))
return TRUE;
if (checkQueryHasSubLink((Node *) (exp->defresult)))
return TRUE;
return FALSE;
}
break;
case T_CaseWhen:
{
CaseWhen *when = (CaseWhen *) node;
if (checkQueryHasSubLink((Node *) (when->expr)))
return TRUE;
if (checkQueryHasSubLink((Node *) (when->result)))
return TRUE;
return FALSE;
}
break;
case T_SubLink:
return TRUE;
default:
elog(NOTICE, "unknown node tag %d in checkQueryHasSubLink()", nodeTag(node));
elog(NOTICE, "Node is: %s", nodeToString(node));
break;
}
return FALSE;
return false;
if (IsA(node, SubLink))
return true; /* abort the tree traversal and return true */
/* Note: we assume the tree has not yet been rewritten by subselect.c,
* therefore we will find bare SubLink nodes and not SUBPLAN nodes.
*/
return expression_tree_walker(node, checkQueryHasSubLink_walker, context);
}