Slow DB query

SELECT
  `t0`.`id` AS `a1`,
  `t0`.`approved` AS `a2`,
  `t0`.`client_id` AS `a3`,
  `t0`.`redirect_uri` AS `a4`,
  `t0`.`user_auth_id` AS `a5`
FROM
  `authentication_holder` `t0`
WHERE
  (
    (
      `t0`.`id` NOT IN (
        SELECT
          `t1`.`id`
        FROM
          `access_token` `t2`,
          `authentication_holder` `t1`
        WHERE
          (`t1`.`id` = `t2`.`auth_holder_id`)
      )
      AND `t0`.`id` NOT IN (
        SELECT
          `t3`.`id`
        FROM
          `refresh_token` `t4`,
          `authentication_holder` `t3`
        WHERE
          (`t3`.`id` = `t4`.`auth_holder_id`)
      )
    )
    AND `t0`.`id` NOT IN (
      SELECT
        `t5`.`id`
      FROM
        `authentication_holder` `t5`,
        `authorization_code` `t6`
      WHERE
        (`t5`.`id` = `t6`.`auth_holder_id`)
    )
  )
LIMIT
  ?, ...

Summary: 

• This seems to be related to the garbage collection, removing tokens
• It is worse when there is a multi pod set up as each one is doing the same query
• Options
  • Redirect read only (or delete) queries to a replica using a proxy
  • Make it possible to configure per pod whether garbage collection is done (not a great model as pods would have different config)
  • Remove the garbage collection completely (optionally) and run in a separate process
  • Stop storing these unnecessary objects anyway

Actions: 

• Berk to try the performance tests with the garbage collection turned off