And (worth repeating here because it was for me so painfully discovered ...) when using SQLite, you should wrap everything in a transaction with explicit commits.   If a transaction is not in progess, SQLite is designed not to use “lazy writes.”   In fact it will physically verify every single write, drastically increasing the I/O activity and bringing everything to its knees.   This is expressly by-design behavior but perhaps it is not intuitive.   When transactions are used, the sucker flies.   I would use them even for SELECTs, although I might be gun-shy on this point.