There was one time that I forgot to specify an index on a table in SQLite and I ran into locking issues with relatively light load. So indexes, where applicable

There was one time that I forgot to specify an index on a table in SQLite and I ran into locking issues with relatively light load. So indexes, where applicable, are a good thing. Also, you can consider sandwiching several updates between BEGIN and END. I've discovered this dramatically improves performance. You just query "BEGIN" to start, execute your updates, then query "END" to process them.