SQLite Forum

Increasing insert performance of an in-memory db
Do you need to have all the data in a single table? Because if you can live with the data split over a couple tables then here's a trick you can try.

Say you have the data over 4 tables, spawn 4 threads, create a SQLite connection for each. Sqlite should be compiled from the begin-concurrent branch. Now start the large transactions in each thread with BEGIN CONCURRENT rather than BEGIN, with each connection writing into a separate table. This way you ensure commits will not conflict, and you can use multiple cores for the transaction execution up until the commit (which remains serialized with respect to other commits). 

Depending on your transaction size, amount of cores/threads and the duration of serial commits you might very well see an appreciable uplift in throughput.