That gives me a new idea, perhaps there should be an option to throw an error (or warning) if a coercion takes place. Now if only there was some way to let NI know I had this idea....
You can use SQLite entirely in memory by using “:memory:” as the filename. Also note that SQLite uses a caching mechanism that makes it effectively in-memory as far as reading goes, as long as the database is smaller than the cache size (2 MB by default).