Move materialized views' is-populated status into their pg_class entries.

Previously this state was represented by whether the view's disk file had
zero or nonzero size, which is problematic for numerous reasons, since it's
breaking a fundamental assumption about heap storage.  This was done to
allow unlogged matviews to revert to unpopulated status after a crash
despite our lack of any ability to update catalog entries post-crash.
However, this poses enough risk of future problems that it seems better to
not support unlogged matviews until we can find another way.  Accordingly,
revert that choice as well as a number of existing kluges forced by it
in favor of creating a pg_class.relispopulated flag column.

1 files changed, 0 insertions, 27 deletions

diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index d32d9014c7e..4c4e1ed8202 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -834,30 +834,3 @@ pg_relation_filepath(PG_FUNCTION_ARGS)
 
 	PG_RETURN_TEXT_P(cstring_to_text(path));
 }
-
-
-/*
- * Indicate whether a relation is scannable.
- *
- * Currently, this is always true except for a materialized view which has not
- * been populated.  It is expected that other conditions for allowing a
- * materialized view to be scanned will be added in later releases.
- */
-Datum
-pg_relation_is_scannable(PG_FUNCTION_ARGS)
-{
-	Oid			relid;
-	Relation	relation;
-	bool		result;
-
-	relid = PG_GETARG_OID(0);
-	relation = try_relation_open(relid, AccessShareLock);
-
-	if (relation == NULL)
-		PG_RETURN_BOOL(false);
-
-	result = RelationIsScannable(relation);
-
-	relation_close(relation, AccessShareLock);
-	PG_RETURN_BOOL(result);
-}