- Patch 6066 by Adrian: PostgreSQL does not return 'affected rows' when doing
  a select statement.  Even though PEAR supports this functionality, it fails
  silently when using PostgreSQL.  We use the db_num_rows() function instead
  to return the amount of rows returned.  (According to Killes, the MySQL
  manual also states that it should not return affected rows on a 'select'
  statement.)