[ask] ci_sessions table do we need to delete it?

[eluser]n1colius[/eluser]
hello, i just want to ask.
i am using ci session with database. so all of our session are on this ci_sessions on our database and it can get pretty many rows considering that the session_id keep changing every 5 minutes.

my question is, do we need to delete it say every one a month / week maybe?
thanks