Index on the cron.job_run_details table #408

The cron.job_run_details table can get big and queries on it can get noticeably slower.

I propose to add indexes to speed up queries.

1 - An index on jobid column (ideally jobid, start_time to be able to order or filter by time). Without index on jobid queries get slow when it is necessary to analyze or check status or logs for specific job.
2 - An index on end_time column. Without such index the recommended clean up query gets slow.

What do you think? Did you consider adding indexes to cron.job_run_details?