> The VACUUM command works by copying the contents of the database into a temporary database file and then overwriting the original with the contents of the temporary file. When overwriting the original, a rollback journal or write-ahead log WAL file is used just as it would be for any other database transaction. This means that when VACUUMing a database, as much as twice the size of the original database file is required in free disk space.

> The VACUUM INTO command works the same way except that it uses the file named on the INTO clause in place of the temporary database and omits the step of copying the vacuumed database back over top of the original database.

Do you use VACUUM (uses a write-ahead log to survive power-off) or VACUUM INTO (as far as I can tell, it doesn't survive power-off during writing, and might corrupt the existing file contents if the filename already exists)?