job_locking_query

lock_jobs = """
      WITH RECURSIVE jobs AS (
        SELECT (j).*, pg_try_advisory_lock($1::integer, (j).id) AS locked
        FROM (
          SELECT j
          FROM #{table} AS j
          WHERE NOT (id = ANY($3))
          AND failed_at IS NULL
          ORDER BY enqueued_at, j.id
          FOR UPDATE SKIP LOCKED
          LIMIT 1
        ) AS t1
        UNION ALL (
          SELECT (j).*, pg_try_advisory_lock($1::integer, (j).id) AS locked
          FROM (
            SELECT (
              SELECT j
              FROM #{table} AS j
              WHERE NOT (id = ANY($3))
              AND failed_at IS NULL
              AND (j.enqueued_at, j.id) > (jobs.enqueued_at, jobs.id)
              ORDER BY enqueued_at, j.id
              FOR UPDATE SKIP LOCKED
              LIMIT 1
            ) AS j
            FROM jobs
            WHERE jobs.id IS NOT NULL
            LIMIT 1
          ) AS t1
        )
      )
      SELECT id, term, enqueued_at, failed_at, fail_reason
      FROM jobs
      WHERE locked
      LIMIT $2
    """

    %{rows: rows} = Postgrex.query!(pg, lock_jobs, [classid(), n, exclude_ids])