diff options
Diffstat (limited to 'src/backend/rewrite/rewriteHandler.c')
| -rw-r--r-- | src/backend/rewrite/rewriteHandler.c | 32 |
1 files changed, 23 insertions, 9 deletions
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c index 3c267ccdcd..b7a96922e9 100644 --- a/src/backend/rewrite/rewriteHandler.c +++ b/src/backend/rewrite/rewriteHandler.c @@ -7,7 +7,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/rewrite/rewriteHandler.c,v 1.153 2005/06/03 23:05:28 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/rewrite/rewriteHandler.c,v 1.154 2005/06/04 19:19:42 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -106,6 +106,8 @@ AcquireRewriteLocks(Query *parsetree) Relation rel; LOCKMODE lockmode; List *newaliasvars; + Index curinputvarno; + RangeTblEntry *curinputrte; ListCell *ll; ++rt_index; @@ -140,8 +142,14 @@ AcquireRewriteLocks(Query *parsetree) * 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); @@ -165,12 +173,17 @@ AcquireRewriteLocks(Query *parsetree) * but it's OK to assume here.) */ Assert(aliasvar->varlevelsup == 0); - if (aliasvar->varno >= rt_index) - elog(ERROR, "unexpected varno %d in JOIN RTE %d", - aliasvar->varno, rt_index); - if (get_rte_attribute_is_dropped( - rt_fetch(aliasvar->varno, parsetree->rtable), - aliasvar->varattno)) + if (aliasvar->varno != curinputvarno) + { + curinputvarno = aliasvar->varno; + if (curinputvarno >= rt_index) + elog(ERROR, "unexpected varno %d in JOIN RTE %d", + curinputvarno, rt_index); + 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 @@ -386,7 +399,8 @@ rewriteRuleAction(Query *parsetree, sub_action = (Query *) ResolveNew((Node *) sub_action, new_varno, 0, - sub_action->rtable, + rt_fetch(new_varno, + sub_action->rtable), parsetree->targetList, event, current_varno); @@ -1206,7 +1220,7 @@ CopyAndAddInvertedQual(Query *parsetree, new_qual = ResolveNew(new_qual, PRS2_NEW_VARNO, 0, - parsetree->rtable, + rt_fetch(rt_index, parsetree->rtable), parsetree->targetList, event, rt_index); |