DELETE FROM batch_step_execution_context bsec
WHERE
  EXISTS (
    SELECT 1 FROM batch_step_execution bse
    join batch_job_execution bje on bje.job_execution_id = bse.job_execution_id
    WHERE bje.start_time < current_date - 14 and bsec.step_execution_id = bse.step_execution_id);

vacuum batch_step_execution_context;