Don't create pg_type entries for sequences or toast tables.

Commit f7f70d5e2 left one inconsistency behind: we're still creating
pg_type entries for the composite types of sequences and toast tables,
but not arrays over those composites.  But there seems precious little
reason to have named composite types for toast tables, and not much more
to have them for sequences (especially given the thought that sequences
may someday not be standalone relations at all).

So, let's close that inconsistency by removing these composite types,
rather than adding arrays for them.  This buys back a little bit of
the initial pg_type bloat added by the previous patch, and could be
a significant savings in a large database with many toast tables.

Aside from a small logic rearrangement in heap_create_with_catalog,
this patch mostly needs to clean up some places that were assuming that
pg_class.reltype always has a valid value.  Those are really pre-existing
bugs, given that it's documented otherwise; notably, the plpgsql changes
fix code that gives "cache lookup failed for type 0" on indexes today.
But none of these seem interesting enough to back-patch.

Also, remove the pg_dump/pg_upgrade infrastructure for propagating
a toast table's pg_type OID into the new database, since we no longer
need that.

Discussion: https://postgr.es/m/761F1389-C6A8-4C15-80CE-950C961F5341@gmail.com

1 files changed, 12 insertions, 34 deletions

diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index a41a3db876c..fd7b3e09203 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -272,7 +272,7 @@ static void binary_upgrade_set_type_oids_by_type_oid(Archive *fout,
 													 PQExpBuffer upgrade_buffer,
 													 Oid pg_type_oid,
 													 bool force_array_type);
-static bool binary_upgrade_set_type_oids_by_rel_oid(Archive *fout,
+static void binary_upgrade_set_type_oids_by_rel_oid(Archive *fout,
 													PQExpBuffer upgrade_buffer, Oid pg_rel_oid);
 static void binary_upgrade_set_pg_class_oids(Archive *fout,
 											 PQExpBuffer upgrade_buffer,
@@ -4493,7 +4493,7 @@ binary_upgrade_set_type_oids_by_type_oid(Archive *fout,
 	destroyPQExpBuffer(upgrade_query);
 }
 
-static bool
+static void
 binary_upgrade_set_type_oids_by_rel_oid(Archive *fout,
 										PQExpBuffer upgrade_buffer,
 										Oid pg_rel_oid)
@@ -4501,48 +4501,23 @@ binary_upgrade_set_type_oids_by_rel_oid(Archive *fout,
 	PQExpBuffer upgrade_query = createPQExpBuffer();
 	PGresult   *upgrade_res;
 	Oid			pg_type_oid;
-	bool		toast_set = false;
 
-	/*
-	 * We only support old >= 8.3 for binary upgrades.
-	 *
-	 * We purposefully ignore toast OIDs for partitioned tables; the reason is
-	 * that versions 10 and 11 have them, but 12 does not, so emitting them
-	 * causes the upgrade to fail.
-	 */
 	appendPQExpBuffer(upgrade_query,
-					  "SELECT c.reltype AS crel, t.reltype AS trel "
+					  "SELECT c.reltype AS crel "
 					  "FROM pg_catalog.pg_class c "
-					  "LEFT JOIN pg_catalog.pg_class t ON "
-					  "  (c.reltoastrelid = t.oid AND c.relkind <> '%c') "
 					  "WHERE c.oid = '%u'::pg_catalog.oid;",
-					  RELKIND_PARTITIONED_TABLE, pg_rel_oid);
+					  pg_rel_oid);
 
 	upgrade_res = ExecuteSqlQueryForSingleRow(fout, upgrade_query->data);
 
 	pg_type_oid = atooid(PQgetvalue(upgrade_res, 0, PQfnumber(upgrade_res, "crel")));
 
-	binary_upgrade_set_type_oids_by_type_oid(fout, upgrade_buffer,
-											 pg_type_oid, false);
-
-	if (!PQgetisnull(upgrade_res, 0, PQfnumber(upgrade_res, "trel")))
-	{
-		/* Toast tables do not have pg_type array rows */
-		Oid			pg_type_toast_oid = atooid(PQgetvalue(upgrade_res, 0,
-														  PQfnumber(upgrade_res, "trel")));
-
-		appendPQExpBufferStr(upgrade_buffer, "\n-- For binary upgrade, must preserve pg_type toast oid\n");
-		appendPQExpBuffer(upgrade_buffer,
-						  "SELECT pg_catalog.binary_upgrade_set_next_toast_pg_type_oid('%u'::pg_catalog.oid);\n\n",
-						  pg_type_toast_oid);
-
-		toast_set = true;
-	}
+	if (OidIsValid(pg_type_oid))
+		binary_upgrade_set_type_oids_by_type_oid(fout, upgrade_buffer,
+												 pg_type_oid, false);
 
 	PQclear(upgrade_res);
 	destroyPQExpBuffer(upgrade_query);
-
-	return toast_set;
 }
 
 static void
@@ -17209,8 +17184,11 @@ dumpSequence(Archive *fout, TableInfo *tbinfo)
 	{
 		binary_upgrade_set_pg_class_oids(fout, query,
 										 tbinfo->dobj.catId.oid, false);
-		binary_upgrade_set_type_oids_by_rel_oid(fout, query,
-												tbinfo->dobj.catId.oid);
+
+		/*
+		 * In older PG versions a sequence will have a pg_type entry, but v14
+		 * and up don't use that, so don't attempt to preserve the type OID.
+		 */
 	}
 
 	if (tbinfo->is_identity_sequence)