How to list tables in a schema postgres?

To list tables in a schema postgres - In addition to the dt match, you can also look into the database catalogue:

SELECT nspname||'.'||relname AS full_rel_name
  FROM pg_class, pg_namespace
 WHERE relnamespace = pg_namespace.oid
   AND nspname = 'yourschemaname'
   AND relkind = 'r';
You can also do it with the more standard information schema, but it tends to be slower:
SELECT table_schema||'.'||table_name AS full_rel_name
  FROM information_schema.tables
 WHERE table_schema = 'yourschemaname';