Early adopter testing and PoCs have shown that the performance of MongoDB Mobile hinders its use in some use cases. So we should look at how we can improve the performance of the underlying storage engine (which wraps sqlite).
For example, currently the write calls are fully synchronous and we do a flush and sync on each call. The performance trade-off for that is too high for many common use cases. We should change the default for the synchronous PRAGMA to NORMAL/1, but also add a new parameter so that users have the choice.
We should explore the available sqlite pragmas that will allow us to achieve better overall performance.