Question

To query GRANTS granted to a table I can use a query like:

SELECT grantee, privilege_type 
FROM information_schema.role_table_grants 
WHERE table_name='mytable'

(see my old question here: Query grants for a table in postgres)

But how I query the GRANTS grated to a sequence?

Answer 1

I’ve looked through the source code, and I can’t find any place that exposes the ACL for sequences through the information_schema tables. (I could have missed something, though.)

PostgreSQL does expose the ACL for sequences in the system catalog pg_class.

SELECT relname, relacl
FROM pg_class
WHERE relkind = 'S'
  AND relacl is not null
  AND relnamespace IN (
      SELECT oid
      FROM pg_namespace
      WHERE nspname NOT LIKE 'pg_%'
        AND nspname != 'information_schema'
);

As far as the information_schema and standard SQL sequences go, PostgreSQL doesn’t support them.

select feature_name, is_supported 
from information_schema.sql_features
where feature_name = 'Sequence generator support';

PostgreSQL is nonconforming in that respect, because it exposes information_schema.sequences without returning “YES” for ‘Sequence generator support’. (That’s an observation, not a criticism of PostgreSQL.)

But, having said all that, I couldn’t find anything in the 2003 SQL standard that exposed those privileges, either. It’s easy to find PRIVILEGE_TYPE in the definition of the ROLE_TABLE_GRANTS view, but there’s nothing like that for sequences in the standard, as far as I can tell.