diff options
Diffstat (limited to 'src/backend/rewrite/rewriteDefine.c')
| -rw-r--r-- | src/backend/rewrite/rewriteDefine.c | 98 |
1 files changed, 87 insertions, 11 deletions
diff --git a/src/backend/rewrite/rewriteDefine.c b/src/backend/rewrite/rewriteDefine.c index b37f36b3e67..a1a9808e5d9 100644 --- a/src/backend/rewrite/rewriteDefine.c +++ b/src/backend/rewrite/rewriteDefine.c @@ -16,6 +16,9 @@ #include "access/heapam.h" #include "access/htup_details.h" +#include "access/multixact.h" +#include "access/transam.h" +#include "access/xact.h" #include "catalog/catalog.h" #include "catalog/dependency.h" #include "catalog/heap.h" @@ -409,7 +412,7 @@ DefineQueryRewrite(char *rulename, * strict, because they will reject relations that once had such but * don't anymore. But we don't really care, because this whole * business of converting relations to views is just a kluge to allow - * loading ancient pg_dump files.) + * dump/reload of views that participate in circular dependencies.) */ if (event_relation->rd_rel->relkind != RELKIND_VIEW) { @@ -500,30 +503,103 @@ DefineQueryRewrite(char *rulename, replace); /* - * Set pg_class 'relhasrules' field TRUE for event relation. If - * appropriate, also modify the 'relkind' field to show that the - * relation is now a view. + * Set pg_class 'relhasrules' field TRUE for event relation. * * Important side effect: an SI notice is broadcast to force all * backends (including me!) to update relcache entries with the new * rule. */ - SetRelationRuleStatus(event_relid, true, RelisBecomingView); + SetRelationRuleStatus(event_relid, true); } - /* - * If the relation is becoming a view, delete the storage files associated - * with it. Also, get rid of any system attribute entries in pg_attribute, - * because a view shouldn't have any of those. + /* --------------------------------------------------------------------- + * If the relation is becoming a view: + * - delete the associated storage files + * - get rid of any system attributes in pg_attribute; a view shouldn't + * have any of those + * - remove the toast table; there is no need for it anymore, and its + * presence would make vacuum slightly more complicated + * - set relkind to RELKIND_VIEW, and adjust other pg_class fields + * to be appropriate for a view * * NB: we had better have AccessExclusiveLock to do this ... - * - * XXX what about getting rid of its TOAST table? For now, we don't. + * --------------------------------------------------------------------- */ if (RelisBecomingView) { + Relation relationRelation; + Oid toastrelid; + HeapTuple classTup; + Form_pg_class classForm; + + relationRelation = heap_open(RelationRelationId, RowExclusiveLock); + toastrelid = event_relation->rd_rel->reltoastrelid; + + /* drop storage while table still looks like a table */ RelationDropStorage(event_relation); DeleteSystemAttributeTuples(event_relid); + + /* + * Drop the toast table if any. (This won't take care of updating + * the toast fields in the relation's own pg_class entry; we handle + * that below.) + */ + if (OidIsValid(toastrelid)) + { + ObjectAddress toastobject; + + /* + * Delete the dependency of the toast relation on the main + * relation so we can drop the former without dropping the latter. + */ + deleteDependencyRecordsFor(RelationRelationId, toastrelid, + false); + + /* Make deletion of dependency record visible */ + CommandCounterIncrement(); + + /* Now drop toast table, including its index */ + toastobject.classId = RelationRelationId; + toastobject.objectId = toastrelid; + toastobject.objectSubId = 0; + performDeletion(&toastobject, DROP_RESTRICT, + PERFORM_DELETION_INTERNAL); + } + + /* + * SetRelationRuleStatus may have updated the pg_class row, so we must + * advance the command counter before trying to update it again. + */ + CommandCounterIncrement(); + + /* + * Fix pg_class entry to look like a normal view's, including setting + * the correct relkind and removal of reltoastrelid/reltoastidxid of + * the toast table we potentially removed above. + */ + classTup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(event_relid)); + if (!HeapTupleIsValid(classTup)) + elog(ERROR, "cache lookup failed for relation %u", event_relid); + classForm = (Form_pg_class) GETSTRUCT(classTup); + + classForm->reltablespace = InvalidOid; + classForm->relpages = 0; + classForm->reltuples = 0; + classForm->relallvisible = 0; + classForm->reltoastrelid = InvalidOid; + classForm->reltoastidxid = InvalidOid; + classForm->relhasindex = false; + classForm->relkind = RELKIND_VIEW; + classForm->relhasoids = false; + classForm->relhaspkey = false; + classForm->relfrozenxid = InvalidTransactionId; + classForm->relminmxid = InvalidMultiXactId; + + simple_heap_update(relationRelation, &classTup->t_self, classTup); + CatalogUpdateIndexes(relationRelation, classTup); + + heap_freetuple(classTup); + heap_close(relationRelation, RowExclusiveLock); } /* Close rel, but keep lock till commit... */ |