Hi Olli,
if I have interpreted the question and the situation in which you are correctly, the way to persist a dialog in DB is to use the db_mode param https://kamailio.org/docs/modules/5.2.x/modules/dialog.html#dialog.p.db_mode
you have 4 possibilities to persist that data in DB
0 - NO_DB - the memory content is not flushed into DB;
1 - REALTIME - any dialog information changes will be reflected into the database immediately.
2 - DELAYED - the dialog information changes will be flushed into DB periodically, based on a timer routine.
3 - SHUTDOWN - the dialog information will be flushed into DB only at shutdown - no runtime updates.
