How to merge contents of SQLite 3.7 WAL file into main database file

Question

With WAL (Write-Ahead-Logging) enabled in SQLite 3.7 (which is the default for Core Data on iOS 7), how do I merge/commit the content from the -wal file back into the main database file?

Answer 1

From the command line, do this:

1. sqlite3 MyDatabase.sqlite
2. VACUUM;
3. CTRL-D to exit the sqlite console.

Done!

The -wal file should now have a size of 0 and everything should be in your main database file.

Answer 2

Do a checkpoint, i.e., execute PRAGMA wal_checkpoint.