Cleanup Metabase database

I'm using self-hosted version of Metabase, using Postgres for Metabase database.

I realized database become too big, I want to know which tables safe to truncate?
I found tables _log _cache... but not sure to be safe to truncate them.

Thank for your help!

Hi @tunh
How big have these tables become?
view_log will mean that some audit trails will not be possible.
query_cache will mean that questions are not cached.