I can't help thinking that you are engaged in a very non-trivial endeavor.

Just for example, you're caching reads while delaying writes. So what happens when someone reads something and it doesn't match what was 'written' but is in delay mode?

This smacks of a Virtual Memory system to be overlayed on a home-rolled filesystem db. I can't help but think you will incur serious agony on this one. Other posters have said to migrate to a real DB with an adaptation layer to kep the current code going, if need be. I agree.

--Bob Niederman, http://bob-n.com