Missing TOAST table for pg_class

[Fabrízio de Royes Mello]

Hi all,

I know it has been discussed before [1] but one of our customers complained
about something weird on one of their multi-tenancy databases (thousands of
schemas with a lot of objects inside and one user by schema).

So when I checked the problem is because the missing TOAST for pg_class,
and is easy to break it by just:

fabrizio=# create table foo (id int);
CREATE TABLE
fabrizio=# do
$$
begin
    for i in 1..2500
    loop
        execute 'create user u' || i;
        execute 'grant all on foo to u' || i;
    end loop;
end;
$$;
ERROR:  row is too big: size 8168, maximum size 8160
CONTEXT:  SQL statement "grant all on foo to u2445"
PL/pgSQL function inline_code_block line 6 at EXECUTE

Attached patch adds the TOAST to pg_class, and let's open again the
discussion around it.

Regards,

[1]
https://www.postgresql.org/message-id/flat/84ddff04-f122-784b-b6c5-3536804495f8%40joeconway.com

-- 
   Fabrízio de Royes Mello         Timbira - http://www.timbira.com.br/
   PostgreSQL: Consultoria, Desenvolvimento, Suporte 24x7 e Treinamento

diff --git a/src/include/catalog/toasting.h b/src/include/catalog/toasting.h
index 51491c4513..729bc2cc66 100644
--- a/src/include/catalog/toasting.h
+++ b/src/include/catalog/toasting.h
@@ -51,6 +51,7 @@ extern void BootstrapToastTable(char *relName,
 /* normal catalogs */
 DECLARE_TOAST(pg_aggregate, 4159, 4160);
 DECLARE_TOAST(pg_attrdef, 2830, 2831);
+DECLARE_TOAST(pg_class, 4179, 4180);
 DECLARE_TOAST(pg_collation, 4161, 4162);
 DECLARE_TOAST(pg_constraint, 2832, 2833);
 DECLARE_TOAST(pg_default_acl, 4143, 4144);
diff --git a/src/test/regress/expected/misc_sanity.out b/src/test/regress/expected/misc_sanity.out
index 8538173ff8..0a2f5cc2a2 100644
--- a/src/test/regress/expected/misc_sanity.out
+++ b/src/test/regress/expected/misc_sanity.out
@@ -100,12 +100,9 @@ ORDER BY 1, 2;
  pg_attribute            | attfdwoptions | text[]
  pg_attribute            | attmissingval | anyarray
  pg_attribute            | attoptions    | text[]
- pg_class                | relacl        | aclitem[]
- pg_class                | reloptions    | text[]
- pg_class                | relpartbound  | pg_node_tree
  pg_index                | indexprs      | pg_node_tree
  pg_index                | indpred       | pg_node_tree
  pg_largeobject          | data          | bytea
  pg_largeobject_metadata | lomacl        | aclitem[]
-(11 rows)
+(8 rows)