Robert Feldt <feldt / ce.chalmers.se> writes:

>> [...bdb...]

> Yes, seems it can handle this load. I tried with a BTree and
> the db-file-size-to-added-key+value-bytes ratio seems to stay
> at 2.5 at least up to 1e5 entries. Running a test with 1e6
> added entries now; insertion time does not seem to scale
> linearly but we'll see about file size.

My experience with bdb has been very good.  Tests with >500
million entries scaled linearly with regards to file-size and
essentially linearly with regards to insert time.  I don't have
too much direct experience with remove time, but update is good,
especially if the entries are not expanding.

The key for excellent performance with bdb is selecting fast
persistent storage for the log files.

~r