You used to be able to open these .db files with SQLLite, however, Cisco has begun encrypting the local db files. This post will provide some history: http://www.pilotmikekc.com/2016/02/12/viewing-cisco-jabber-local-history-file/. See the post from 9/15/17 by Mike. It is a bummer, for sure.
May I expand this question slightly: Is there ANYWHERE (OID or /var) on the CUPS system that retains ANY part of this same detail?
Specifically, is the RAW NUMBER OF IM TRANSMISSIONS (rx/tx) stored in CUPS?
is there an OID?
is there a log that tracks this?
I'm trying to use "show perf query counter "Cisco XCP JSM Session Counters" JsmSessionMessage " but from what I see this clears REALLY quickly (60 seconds) so monitoring via cli is really hard to automate/monitor.