I'm interested in answering the question "has the contents of this database changed in any way" as efficiently as possible. I want to do this for caching purposes - I'd like to be able to cache various things relating to an infrequently changed database but invalidate that cache if even a single row has been inserted or updated. I've successfully used `PRAGMA schema_version` to invalidate a cache when the database schema changes, but now I'm looking to do it based on the file contents instead. Options I'm considering: - Calculating the MD5 hash of the file contents on disk, which runs pretty fast (but not fast enough to do it often) - Adding triggers to every single database table which increment a counter any time those tables have content inserted/updated/deleted I'm pretty sure that second option would work correctly (I'm not at all worried about the additional overhead on writes), but I'm wondering if there's a solution I haven't considered that would be even better.