This should not be needed, the SQL engines usually all do this internally, for the exact reason you are trying to do it. I'm not 100% sure right this moment that SQLite does it, or how effective it is, but I have to think that with all the years of chasing faster an faster total execution times and squeezing every last drop of efficiency out of the engine, the SQLite devs would not have neglected this rather obvious first point of optimization. Have you any observations/measurements that leads you to think the opposite?