SQL bind peeking

SELECT *
FROM (
    SELECT regexp_substr(request, 'from\s+[^\s]+', 1, 1, 'in') AS "table",
           regexp_substr(request, 'where\s+id\s+=\s+[^\s]+', 1, 1, 'in') AS "filter"
      FROM query_requests) AS queries
WHERE queries.filter IS NOT NULL;

daniel=> \g
  table   |        filter         
----------+-----------------------
 from foo | where id = 683679;
 from egg | where id = 683679;
 from bar | where id = 9268854;
 from bar | where id = hash('a');
 from foo | where id = hash('a');
 from foo | where id = 000;
 from foo | where id = 666;
 from foo | where id = 109;
 from foo | where id = 16;
(9 rows)

SELECT *
FROM (
    SELECT regexp_substr(request, 'from\s+([^\s]+)', 1, 1, 'in', 1) AS "table",
           regexp_substr(request, 'where\s+id\s+=\s+([^\s]+)', 1, 1, 'in', 1) AS "filter"
      FROM query_requests) AS queries
WHERE queries.filter IS NOT NULL;

daniel=> \g
 table |   filter   
-------+------------
 foo   | 683679;
 egg   | 683679;
 bar   | 9268854;
 bar   | hash('a');
 foo   | hash('a');
 foo   | 000;
 foo   | 666;
 foo   | 109;
 foo   | 16;
(9 rows)