show grants for PostgreSQL

pg_show_grants.sql

select
  pg_user.usename,
  t1.nspname,
  t1.relname, 
  relacl.privilege_type,
  relacl.is_grantable
from (
  select
    pg_namespace.nspname,
    pg_class.relname,
    coalesce(pg_class.relacl, ('{' || pg_user.usename || '=arwdDxt/' || pg_user.usename || '}')::aclitem[]) as relacl
  from
    pg_class
    inner join pg_namespace on pg_class.relnamespace = pg_namespace.oid
    inner join pg_user on pg_class.relowner = pg_user.usesysid
  where
    pg_namespace.nspname !~ '^pg_'
    and pg_namespace.nspname != 'information_schema'
) as t1
cross join aclexplode(t1.relacl) as relacl
inner join pg_user on relacl.grantee = pg_user.usesysid
order by
  pg_user.usename,
  t1.nspname,
  t1.relname,
  relacl.privilege_type

screenshot.md