[pybsddb] Making calls to keys() more efficient (or, how to do inequality gets on keys?)

[Denis Papathanasiou]

Thank you to everyone who replied.

Unfortunately, the db in question is not a btree, so I couldn't use the 
cursor idea.

I wound up using a more frequent purge interval in the short-term, which 
gave me enough time to put the timestamp in the value, where I could use 
a secondary index to get the range of expired keys I needed.

> If you are actually using so many keys, you can use range key request in
> Berkeley DB. I am not sure we support it yet in pybsddb. I can not check
> it now. But if not, and you need it, just ask and I would add it to the
> new pybsddb version.

Is range key request limited to btrees? If not, then I'd vote for it to 
be included in pybsddb as well.