Comments of derived tables

WITH named_objects AS (

SELECT 
c.oid,
n.nspname AS schema_name, 
c.relname AS table_name,
c.relname AS commented_object_name,
CASE WHEN c.relkind='v' THEN 'VIEW'
WHEN c.relkind='m' THEN 'MATERIALIZED VIEW' END AS commented_object_type
FROM pg_namespace AS n INNER JOIN pg_authid AS a ON n.nspowner=a.oid
INNER JOIN pg_class AS c ON n.oid=c.relnamespace
WHERE (n.nspname='public' OR a.rolname<>'postgres')
AND relkind IN ('v','m')

UNION SELECT 
tr.oid,
n.nspname AS schema_name,
c.relname AS table_name,
tr.tgname AS commented_object_name,
'TRIGGER' AS commented_object_type
FROM pg_trigger tr INNER JOIN pg_class c ON tr.tgrelid=c.oid
INNER JOIN pg_namespace AS n ON n.oid=c.relnamespace
INNER JOIN pg_authid AS a ON n.nspowner=a.oid
WHERE (n.nspname='public' OR a.rolname<>'postgres')
AND tr.tgisinternal='f'
AND c.relkind IN ('v','m')

UNION SELECT 
r.oid,
n.nspname AS schema_name,
c.relname AS table_name,
r.rulename AS commented_object_name,
CASE WHEN is_instead=TRUE THEN 'INSTEAD OF ' END ||
CASE WHEN ev_type='1' THEN 'SELECT'
WHEN ev_type='2' THEN 'UPDATE'
WHEN ev_type='3' THEN 'INSERT'
WHEN ev_type='4' THEN 'DELETE' END || ' RULE' AS commented_object_type
FROM pg_rewrite r INNER JOIN pg_class c ON r.ev_class=c.oid
INNER JOIN pg_namespace AS n ON n.oid=c.relnamespace
INNER JOIN pg_authid AS a ON n.nspowner=a.oid
WHERE (n.nspname='public' OR a.rolname<>'postgres')
AND c.relkind IN ('v','m')

),
named_user_defined_objects AS (
SELECT oid, schema_name, table_name, commented_object_name, commented_object_type
FROM named_objects nob
WHERE NOT EXISTS (SELECT 1
FROM pg_catalog.pg_depend d 
WHERE EXISTS (SELECT 1 FROM pg_catalog.pg_extension e WHERE d.refobjid=e.oid) AND
d.objid=nob.oid)
),
columns AS (SELECT 
c.oid,
n.nspname AS schema_name,
c.relname AS table_name,
at.attname AS commented_object_name,
'COLUMN' AS commented_object_type,
attnum AS ordinal_position
FROM pg_attribute at INNER JOIN pg_class c ON at.attrelid=c.oid
INNER JOIN pg_namespace AS n ON n.oid=c.relnamespace
INNER JOIN pg_authid AS a ON n.nspowner=a.oid
WHERE (nspname='public' OR rolname<>'postgres')
AND c.relkind IN ('v','m')
AND at.attisdropped='f'
AND at.attnum>0
AND NOT EXISTS (SELECT 1
FROM pg_catalog.pg_depend d 
WHERE EXISTS (SELECT 1 FROM pg_catalog.pg_extension e WHERE d.refobjid=e.oid) AND
d.objid=c.oid))
SELECT schema_name, table_name, commented_object_name, commented_object_type, description AS comment
FROM named_user_defined_objects AS n INNER JOIN pg_catalog.pg_description AS d ON n.oid=d.objoid
WHERE objsubid=0
UNION SELECT schema_name, table_name, commented_object_name, commented_object_type, description AS comment
FROM columns AS c INNER JOIN pg_catalog.pg_description AS d ON c.oid=d.objoid AND c.ordinal_position=d.objsubid
ORDER BY schema_name, table_name, commented_object_type, commented_object_name;