All empty tables in a Postgresql database

empty_tables.sql

drop FUNCTION empty_tables;

CREATE OR REPLACE FUNCTION empty_tables()
  RETURNS TABLE(name text) AS
$BODY$
DECLARE
    t record;
    v_sql text;
    hasdata bool;
BEGIN
    DROP TABLE IF EXISTS tmp_emptytables;
    CREATE TEMP TABLE tmp_emptytables (name text);
    FOR t in (SELECT table_schema, table_name 
              FROM INFORMATION_SCHEMA.tables 
              WHERE table_schema NOT IN('information_schema','pg_catalog')
                AND table_name <> 'tmp_emptytables')
    LOOP
        v_sql := 'SELECT true as hasdata FROM '||quote_ident(t.table_schema)||'.'||quote_ident(t.table_name)||' LIMIT 1';
        --RAISE INFO 'v_sql:%',v_sql;
        EXECUTE v_sql INTO hasdata;
        IF hasdata IS NULL THEN
            insert into tmp_emptytables SELECT quote_ident(t.table_schema)||'.'||quote_ident(t.table_name);
        END IF;
    END LOOP;
    RETURN QUERY (SELECT * FROM tmp_emptytables ORDER BY 1);
END
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;

select * from empty_tables();

/* --or just this query:
SELECT nspname || '.' || relname AS "relation" 
FROM pg_class C LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace) 
WHERE nspname NOT IN ('pg_catalog', 'information_schema','pg_toast') AND pg_relation_size(C.oid)=0 
ORDER BY 1;
*/