diff options
| -rw-r--r-- | src/backend/rewrite/rewriteDefine.c | 68 |
1 files changed, 33 insertions, 35 deletions
diff --git a/src/backend/rewrite/rewriteDefine.c b/src/backend/rewrite/rewriteDefine.c index 8444bd91384..da0d84ad9d5 100644 --- a/src/backend/rewrite/rewriteDefine.c +++ b/src/backend/rewrite/rewriteDefine.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteDefine.c,v 1.51 2000/09/12 04:49:09 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteDefine.c,v 1.52 2000/09/12 20:38:09 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -200,40 +200,16 @@ DefineQueryRewrite(RuleStmt *stmt) foreach(l, action) { query = (Query *) lfirst(l); - if (query->resultRelation == 1) + if (query->resultRelation == PRS2_OLD_VARNO) { elog(ERROR, "rule actions on OLD currently not supported" "\n\tuse views or triggers instead"); } - if (query->resultRelation == 2) + if (query->resultRelation == PRS2_NEW_VARNO) { elog(ERROR, "rule actions on NEW currently not supported" "\n\tuse triggers instead"); } - - if (event_relation->rd_rel->relkind != RELKIND_VIEW) - { - HeapScanDesc scanDesc; - HeapTuple tuple; - /* - * A relation is about to become a view. - * check that the relation is empty because - * the storage for the relation is going to - * be deleted. - */ - - scanDesc = heap_beginscan(event_relation, 0, SnapshotNow, 0, NULL); - tuple = heap_getnext(scanDesc, 0); - if (HeapTupleIsValid(tuple)) - elog(ERROR, "relation %s is not empty. Cannot convert to view", event_obj->relname); - - /* don't need heap_freetuple because we never got a valid tuple */ - heap_endscan(scanDesc); - - - RelisBecomingView = true; - } - } /* @@ -333,7 +309,6 @@ DefineQueryRewrite(RuleStmt *stmt) /* * ... and finally the rule must be named _RETviewname. */ - expected_name = MakeRetrieveViewRuleName(event_obj->relname); if (strcmp(expected_name, stmt->rulename) != 0) { @@ -341,6 +316,29 @@ DefineQueryRewrite(RuleStmt *stmt) event_obj->relname, expected_name); } pfree(expected_name); + + /* + * Are we converting a relation to a view? + * + * If so, check that the relation is empty because the storage + * for the relation is going to be deleted. + */ + if (event_relation->rd_rel->relkind != RELKIND_VIEW) + { + HeapScanDesc scanDesc; + HeapTuple tuple; + + scanDesc = heap_beginscan(event_relation, 0, SnapshotNow, 0, NULL); + tuple = heap_getnext(scanDesc, 0); + if (HeapTupleIsValid(tuple)) + elog(ERROR, "Relation \"%s\" is not empty. Cannot convert it to view", + event_obj->relname); + + /* don't need heap_freetuple because we never got a valid tuple */ + heap_endscan(scanDesc); + + RelisBecomingView = true; + } } /* @@ -363,7 +361,7 @@ DefineQueryRewrite(RuleStmt *stmt) is_instead, event_attype); /* discard rule if it's null action and not INSTEAD; it's a no-op */ - if (action != NULL || is_instead) + if (action != NIL || is_instead) { Relation relationRelation; HeapTuple tuple; @@ -382,8 +380,8 @@ DefineQueryRewrite(RuleStmt *stmt) /* * Set pg_class 'relhasrules' field TRUE for event relation. - * Also modify the 'relkind' field to show that the relation is - * now a view. + * If appropriate, also modify the 'relkind' field to show that + * the relation is now a view. * * Important side effect: an SI notice is broadcast to force all * backends (including me!) to update relcache entries with the new @@ -398,8 +396,8 @@ DefineQueryRewrite(RuleStmt *stmt) */ relationRelation = heap_openr(RelationRelationName, RowExclusiveLock); tuple = SearchSysCacheTupleCopy(RELOID, - ObjectIdGetDatum(ev_relid), - 0, 0, 0); + ObjectIdGetDatum(ev_relid), + 0, 0, 0); Assert(HeapTupleIsValid(tuple)); /* Do the update */ @@ -420,12 +418,12 @@ DefineQueryRewrite(RuleStmt *stmt) /* * IF the relation is becoming a view, delete the storage - * files associated with it. + * files associated with it. NB: we had better have AccessExclusiveLock + * to do this ... */ if (RelisBecomingView) smgrunlink(DEFAULT_SMGR, event_relation); - /* Close rel, but keep lock till commit... */ heap_close(event_relation, NoLock); } |