I've been puzzled by lmdb's free list use. In some experiments, I've

been seeing that it sometimes grabs pages from the end instead of

using free list pages. This means that the number of pages used

tends to grow until it uses them all. I've tried increasing the map size

(to even quite a large value), and ensuring that write transactions are 

not held open long but that doesn't seem to help. I've tried with

subdatabases and without subdatabases. It does appear to increase

faster when overflow pages are used, but even without overflow

pages the effect occurs. I can see in the code some places where it

might choose not to use the free list, but I haven't been able to

identify a problem in the code. Wondering whether anyone else

has observed this also. The library otherwise looks quite useful
and performant. Using lmdb via python (0.92). Thanks.

Patrick