[MSNoise] How to delete old records?

Dear everyone, I used to use MSnoise to do some calculation, and the work is done. Now I want to do something new, but meet a problem After using 'msnoise populate' and 'msnoise sacan_archive --init' to import new data, I found the 'data availability' and 'job' record in database(in admin web-interface) still have old records, but I don't need them! And I worry about if old ones wound disturb my new jobs. How can I delete old record in 'data availability' and 'job'? I don't want to do it manually cause it's a realy a lot. Thanks for help！ Shuye Huang