What are the .db-shm and .db-wal extensions in Sqlite databases?

Question

I am seeing some strange behavior with my application and the state of its database file after running some tests that close the database, delete it, and replace it with a t

Answer 1

I do not yet have enough reputation to just add a comment to satur9nine's answer, so I'll pile on here.

As per the SQLite docs, the DB-SHM file is a Shared Memory file, only present when SQLite it running in WAL (Write-Ahead Log) mode. This is because in WAL mode, db connections sharing the same db file must all update the same memory location used as index for the WAL file, to prevent conflicts.

As for WAL file, as hinted above, it is a write log/journal, useful for commits/rollback purposes. If the DB is not running, it is perfectly OK to delete this file, and in fact it would be automatically deleted when restarting the DB if one exists (since it's only useful when the DB is actively writing/committing data).