Yes, your guess is write: my unit-test busy CPU-time is while my **sqlite3_busy_handler** callback is being called million of times due to the **server busy** condition. <br>This is when sqlite is being attacked by other worker-threads of my unit-test. The interesting thing that I did find is that when I configure sqlite to **TRUNCATE-NORMAL** the CPU usage of my app is around 30% while **WAL-NORMAL** brings it up to 99%. <br>I should mention that measuring performance the WAL performance is at least twice as fast as TRUNCATE.