var/log/cabal files question

I see some .trc files in var/log/cabal folder.

Can anybody tell me how to manage this files :

******.log.swp Files
******.trc Files
and eventualy when are ******.log Files generated? is It in cabal Service?

well im expecting answers like ... log.swp files are created when u.. bla

Should I erase log.swp Files?... can I delete all those ******_4982984 trc files
I mean .. I had some CashDBAgent_#####.trc files... but I am not sure if this is a problem ...

Can I erase ALL var/log/cabal folder files and generate Them all again?

god bless u