diff options
Diffstat (limited to 'src/backend/rewrite/rewriteHandler.c')
| -rw-r--r-- | src/backend/rewrite/rewriteHandler.c | 91 |
1 files changed, 56 insertions, 35 deletions
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c index 4ad87f16ba4..ca9a2c27d8d 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 1.59 1999/10/02 04:42:04 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.60 1999/10/07 04:23:15 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -818,12 +818,13 @@ ApplyRetrieveRule(Query *parsetree, int rt_index, int relation_level, Relation relation, + bool relWasInJoinSet, int *modified) { Query *rule_action = NULL; Node *rule_qual; List *rtable, - *rt, + *addedrtable, *l; int nothing, rt_length; @@ -844,19 +845,23 @@ ApplyRetrieveRule(Query *parsetree, nothing = TRUE; rtable = copyObject(parsetree->rtable); - foreach(rt, rtable) - { - RangeTblEntry *rte = lfirst(rt); + rt_length = length(rtable); /* original length, not counting rule */ - /* - * this is to prevent add_missing_vars_to_base_rels() from adding - * a bogus entry to the new target list. - */ - rte->inFromCl = false; + addedrtable = copyObject(rule_action->rtable); + + /* If the original rel wasn't in the join set, none of its spawn is. + * If it was, then leave the spawn's flags as they are. + */ + if (! relWasInJoinSet) + { + foreach(l, addedrtable) + { + RangeTblEntry *rte = lfirst(l); + rte->inJoinSet = false; + } } - rt_length = length(rtable); - rtable = nconc(rtable, copyObject(rule_action->rtable)); + rtable = nconc(rtable, addedrtable); parsetree->rtable = rtable; /* FOR UPDATE of view... */ @@ -1006,10 +1011,14 @@ fireRIRrules(Query *parsetree) RuleLock *rules; RewriteRule *rule; RewriteRule RIRonly; + bool relWasInJoinSet; int modified = false; int i; List *l; + /* don't try to convert this into a foreach loop, because + * rtable list can get changed each time through... + */ rt_index = 0; while (rt_index < length(parsetree->rtable)) { @@ -1017,46 +1026,57 @@ fireRIRrules(Query *parsetree) rte = nth(rt_index - 1, parsetree->rtable); - if (!rangeTableEntry_used((Node *) parsetree, rt_index, 0)) + /* + * If the table is not one named in the original FROM clause + * then it must be referenced in the query, or we ignore it. + * This prevents infinite expansion loop due to new rtable + * entries inserted by expansion of a rule. + */ + if (! rte->inFromCl && rt_index != parsetree->resultRelation && + ! rangeTableEntry_used((Node *) parsetree, rt_index, 0)) { - - /* - * Unused range table entries must not be marked as coming - * from a clause. Otherwise the planner will generate joins - * over relations that in fact shouldn't be scanned at all and - * the result will contain duplicates - * - * Jan - * - */ - rte->inFromCl = FALSE; + /* Make sure the planner ignores it too... */ + rte->inJoinSet = false; continue; } rel = heap_openr(rte->relname, AccessShareLock); - if (rel->rd_rules == NULL) + rules = rel->rd_rules; + if (rules == NULL) { heap_close(rel, AccessShareLock); continue; } - rules = rel->rd_rules; - locks = NIL; + relWasInJoinSet = rte->inJoinSet; /* save before possibly clearing */ /* * Collect the RIR rules that we must apply */ + locks = NIL; for (i = 0; i < rules->numLocks; i++) { rule = rules->rules[i]; if (rule->event != CMD_SELECT) continue; - if (rule->attrno > 0 && - !attribute_used((Node *) parsetree, - rt_index, - rule->attrno, 0)) - continue; + if (rule->attrno > 0) + { + /* per-attr rule; do we need it? */ + if (! attribute_used((Node *) parsetree, + rt_index, + rule->attrno, 0)) + continue; + } + else + { + /* Rel-wide ON SELECT DO INSTEAD means this is a view. + * Remove the view from the planner's join target set, + * or we'll get no rows out because view itself is empty! + */ + if (rule->isInstead) + rte->inJoinSet = false; + } locks = lappend(locks, rule); } @@ -1083,6 +1103,7 @@ fireRIRrules(Query *parsetree) rt_index, RIRonly.attrno == -1, rel, + relWasInJoinSet, &modified); } @@ -2012,10 +2033,10 @@ Except_Intersect_Rewrite(Query *parsetree) * If the Select Query node has aggregates in use add all the * subselects to the HAVING qual else to the WHERE qual */ - if (intersect_node->hasAggs == false) - AddQual(intersect_node, (Node *) n); - else + if (intersect_node->hasAggs) AddHavingQual(intersect_node, (Node *) n); + else + AddQual(intersect_node, (Node *) n); /* Now we got sublinks */ intersect_node->hasSubLinks = true; |