Berkeley DB Family

Hi,

Has anyone got experience in selecting an extent size for BDB Queue toplogy databases? I'm trying to pick an extent size for a database and have come to the conclusion that throughput of data through the queue is a good guide when selecting an extent size. I.e. make your extent size proportional to the amount of data which moved through the queue. For example: Assuming you're not too worried about disc space, for a queue with 50MB of data throughput pick an extent size of 10MB.

Has anyone got any ideas whether this approach is sound?

The technical reference makes the following statement, which although accurate isn't very helpful:

In choosing an extent size there is a tradeoff between the amount of disk space used and the overhead of creating and deleting files. If the extent size is too small, the system will pay a performance penalty, creating and deleting files frequently. In addition, if the active part of the queue spans many files, all those files will need to be open at the same time, consuming system and process file resources.

Regards, Sebastian.