You would need to use an sqlite3 client to make sense of that file.
rasterisk -x "database show"
will "dump" it's content. ( redirect that into a text file also JIC.)
If restarting asterisk doesn't fix it and you have no other process using it (which is unlikely apart from occasionally FreePBX reloads), I would probably rename that file while asterisk is stopped, It should be rebuilt on an asterisk start. You will loose some "state" like blacklists etc. but if they are important you can retrieve that from your dump file.
For reference
https://wiki.asterisk.org/wiki/display/AST/Asterisk+Internal+Database