From 15455e14b84a75aa4c663712f3e75113fbffe7d8 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 1 Nov 1999 05:18:31 +0000
Subject: [PATCH] Eliminate RewritePreprocessQuery, which was taking an
unreasonable amount of time to clean up after a vanished parser problem.
Don't call fireRIRonSubselect when we know there are no subselects, either.
---
src/backend/rewrite/rewriteHandler.c | 94 +++++++---------------------
1 file changed, 22 insertions(+), 72 deletions(-)
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
index e36879a4ad3..1051ddb1469 100644
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -6,7 +6,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.61 1999/10/17 23:50:43 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.62 1999/11/01 05:18:31 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -491,7 +491,7 @@ modifyAggrefMakeSublink(Expr *origexp, Query *parsetree)
target = (Var *) (aggref->target);
if (! IsA(target, Var))
elog(ERROR, "rewrite: aggregates of views only allowed on simple variables for now");
- rte = (RangeTblEntry *) nth(target->varno - 1, parsetree->rtable);
+ rte = rt_fetch(target->varno, parsetree->rtable);
resdom = makeNode(Resdom);
resdom->resno = 1;
@@ -916,7 +916,7 @@ ApplyRetrieveRule(Query *parsetree,
if (relation_level)
{
- RangeTblEntry *rte = (RangeTblEntry *) nth(rt_index - 1, rtable);
+ RangeTblEntry *rte = rt_fetch(rt_index, rtable);
parsetree = (Query *) apply_RIR_view((Node *) parsetree,
rt_index, rte,
@@ -1024,7 +1024,7 @@ fireRIRrules(Query *parsetree)
{
++rt_index;
- rte = nth(rt_index - 1, parsetree->rtable);
+ rte = rt_fetch(rt_index, parsetree->rtable);
/*
* If the table is not one named in the original FROM clause
@@ -1110,7 +1110,8 @@ fireRIRrules(Query *parsetree)
heap_close(rel, AccessShareLock);
}
- fireRIRonSubselect((Node *) parsetree, NULL);
+ if (parsetree->hasSubLinks)
+ fireRIRonSubselect((Node *) parsetree, NULL);
parsetree->qual = modifyAggrefQual(parsetree->qual, parsetree);
@@ -1246,8 +1247,7 @@ fireRules(Query *parsetree,
break;
}
- rte = (RangeTblEntry *) nth(parsetree->resultRelation - 1,
- parsetree->rtable);
+ rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
if (!rte->skipAcl)
{
acl_rc = pg_aclcheck(rte->relname,
@@ -1546,50 +1546,6 @@ QueryRewriteOne(Query *parsetree)
}
-/* ----------
- * RewritePreprocessQuery -
- * adjust details in the parsetree, the rule system
- * depends on
- * ----------
- */
-static void
-RewritePreprocessQuery(Query *parsetree)
-{
- /* ----------
- * if the query has a resultRelation, reassign the
- * result domain numbers to the attribute numbers in the
- * target relation. FixNew() depends on it when replacing
- * *new* references in a rule action by the expressions
- * from the rewritten query.
- * resjunk targets are somewhat arbitrarily given a resno of 0;
- * this is to prevent FixNew() from matching them to var nodes.
- * ----------
- */
- if (parsetree->resultRelation > 0)
- {
- RangeTblEntry *rte;
- Relation rd;
- List *tl;
-
- rte = (RangeTblEntry *) nth(parsetree->resultRelation - 1,
- parsetree->rtable);
- rd = heap_openr(rte->relname, AccessShareLock);
-
- foreach(tl, parsetree->targetList)
- {
- TargetEntry *tle = (TargetEntry *) lfirst(tl);
-
- if (! tle->resdom->resjunk)
- tle->resdom->resno = attnameAttNum(rd, tle->resdom->resname);
- else
- tle->resdom->resno = 0;
- }
-
- heap_close(rd, AccessShareLock);
- }
-}
-
-
/*
* BasicQueryRewrite -
* rewrite one query via query rewrite system, possibly returning 0
@@ -1606,20 +1562,12 @@ BasicQueryRewrite(Query *parsetree)
/*
* Step 1
*
- * There still seems something broken with the resdom numbers so we
- * reassign them first.
- */
- RewritePreprocessQuery(parsetree);
-
- /*
- * Step 2
- *
* Apply all non-SELECT rules possibly getting 0 or many queries
*/
querylist = QueryRewriteOne(parsetree);
/*
- * Step 3
+ * Step 2
*
* Apply all the RIR rules on each query
*/
@@ -1629,17 +1577,20 @@ BasicQueryRewrite(Query *parsetree)
/*
* If the query was marked having aggregates, check if this is
- * still true after rewriting. This check must get expanded when
- * someday aggregates can appear somewhere else than in the
- * targetlist or the having qual.
+ * still true after rewriting. Ditto for sublinks.
+ *
+ * This check must get expanded when someday aggregates can appear
+ * somewhere else than in the targetlist or the having qual.
*/
if (query->hasAggs)
query->hasAggs = checkQueryHasAggs((Node *) (query->targetList))
|| checkQueryHasAggs((Node *) (query->havingQual));
- query->hasSubLinks = checkQueryHasSubLink((Node *) (query->qual))
- || checkQueryHasSubLink((Node *) (query->havingQual));
+ if (query->hasSubLinks)
+ query->hasSubLinks = checkQueryHasSubLink((Node *) (query->qual))
+ || checkQueryHasSubLink((Node *) (query->havingQual));
results = lappend(results, query);
}
+
return results;
}
@@ -1809,8 +1760,7 @@ Except_Intersect_Rewrite(Query *parsetree)
Node *limitOffset,
*limitCount;
CmdType commandType = CMD_SELECT;
- List *rtable_insert = NIL;
-
+ RangeTblEntry *rtable_insert = NULL;
List *prev_target = NIL;
/*
@@ -1837,15 +1787,15 @@ Except_Intersect_Rewrite(Query *parsetree)
*/
if (parsetree->commandType == CMD_INSERT)
{
- parsetree->commandType = CMD_SELECT;
- commandType = CMD_INSERT;
- parsetree->resultRelation = 0;
-
/*
* The result relation ( = the one to insert into) has to be
* attached to the rtable list of the new top node
*/
- rtable_insert = nth(length(parsetree->rtable) - 1, parsetree->rtable);
+ rtable_insert = rt_fetch(parsetree->resultRelation, parsetree->rtable);
+
+ parsetree->commandType = CMD_SELECT;
+ commandType = CMD_INSERT;
+ parsetree->resultRelation = 0;
}
/*
--
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