Increasing memory usage on successive LMDB reads

Hi

I'm using LMDB (original C interface) to store and read some data. However, I notice that my resident memory usage (RES in `htop`) keeps rising with each call to mdb_get with unique keys. It does not change if I do a repeated call to mdb_get with a key I've used before.

It looks like mdb_get is caching the reads, but I want to make sure what effect it is really having on my system. Is there some way to limit the amount of memory lmdb can use for this? Or is it something strange and should not be happening?

Thanks Rohit