So far, SQLite did support transaction control, but entirely in memory. Version 3.7.0+ of SQLite now have a Write-Ahead Logging feature that allow more speed and flexibility to SQLite to manage record locking and journal management. This feature is called ‘wal’ in SQLite 3.7.0+. To activate WAL on a SQLite database, start up SQLite and type the following at the sqlite> prompt:
If this returns wal, then you are done, else, your SQLite version does not have wal support. You will need to stick to the older journal mode.
Note that journal_mode = wal will survive database closures. If you want the older journal_mode back, then type the following at the sqlite> prompt:
More information on WAL is available here http://www.sqlite.org/wal.html.