I'm currently writing a module for creating read and write locks for these types of databases. Although I'm currently writting it for MLDBM d/bases using DB_File, I'll probably make it more adaptable for my own future use as well.

It just allows you to create a read/write lock, read or write your data and then flush it to the database without anyone contending your access.

I've got it working and have test run it concurrently in an ending loop with 3 other processes to see if the read and write locks hold and release and to make sure it deals with contention properly. I just need to tidy it up a bit and then I'll post it here for you to use if you like.

Cheers,
Dean