CiviCRM MySQL query causing out of memory

SELECT DISTINCT( contact_a.id ) AS id
FROM   civicrm_contact contact_a
       LEFT JOIN civicrm_group_contact `civicrm_group_contact-605`
         ON contact_a.id = `civicrm_group_contact-605`.contact_id
       LEFT JOIN civicrm_group_contact `civicrm_group_contact-608`
         ON contact_a.id = `civicrm_group_contact-608`.contact_id
       LEFT JOIN civicrm_group_contact `civicrm_group_contact-612`
         ON contact_a.id = `civicrm_group_contact-612`.contact_id
WHERE  ( (( ( `civicrm_group_contact-605`.group_id IN ( 605 )
              AND `civicrm_group_contact-605`.status IN ( "Added" ) )
             OR (( contact_a.id IN (SELECT DISTINCT( contact_a.id ) AS id
                                    FROM   civicrm_contact contact_a
                   LEFT JOIN civicrm_value_1_riding__circonscription
                     ON
                civicrm_value_1_riding__circonscription.entity_id
                =
                contact_a.id
                                    WHERE  (
          civicrm_value_1_riding__circonscription.riding
          =
          47001
                                           )
                                           AND ( 1 )
                                           AND 1)
                   AND contact_a.id NOT IN (SELECT contact_id
                                            FROM   civicrm_group_contact
                                            WHERE
                       civicrm_group_contact.group_id = 605
                       AND civicrm_group_contact.status =
                           "Removed")
                     )) ))
          OR (( ( `civicrm_group_contact-608`.group_id IN ( 608 )
                  AND `civicrm_group_contact-608`.status IN ( "Added" ) )
                 OR (( contact_a.id IN (SELECT DISTINCT( contact_a.id ) AS id
                                        FROM   civicrm_contact contact_a
                       LEFT JOIN civicrm_value_1_riding__circonscription
                         ON
                    civicrm_value_1_riding__circonscription.entity_id
                    =
                    contact_a.id
                                        WHERE  (
              civicrm_value_1_riding__circonscription.riding
              =
              47004
                                               )
                                               AND ( 1 )
                                               AND 1)
                       AND contact_a.id NOT IN (SELECT contact_id
                                                FROM   civicrm_group_contact
                                                WHERE
                           civicrm_group_contact.group_id =
                           608
                           AND civicrm_group_contact.status
                               =
                               "Removed")
                         )) ))
          OR (( ( `civicrm_group_contact-612`.group_id IN ( 612 )
                  AND `civicrm_group_contact-612`.status IN ( "Added" ) )
                 OR (( contact_a.id IN (SELECT DISTINCT( contact_a.id ) AS id
                                        FROM   civicrm_contact contact_a
                       LEFT JOIN civicrm_value_1_riding__circonscription
                         ON
                    civicrm_value_1_riding__circonscription.entity_id
                    =
                    contact_a.id
                                        WHERE  (
              civicrm_value_1_riding__circonscription.riding
              =
              47008
                                               )
                                               AND ( 1 )
                                               AND 1)
                       AND contact_a.id NOT IN (SELECT contact_id
                                                FROM   civicrm_group_contact
                                                WHERE
                           civicrm_group_contact.group_id =
                           612
                           AND civicrm_group_contact.status
                               =
                               "Removed")
                         )) )) );