BerkeleyDB Hash vs Btree on FreeBSD and Linux

[Li-Wen Hsu]

On Wed, Jul 1, 2020 at 6:07 PM Nick Kostirya via freebsd-stable
<freebsd-stable at freebsd.org> wrote:
>
> Hello.
>
> I noticed that BerkeleyDB Hash is VERY slow compared to BerkeleyDB Btree on FreeBSD (UFS or ZFS).
> But they (Hash and Btree) have roughly the same performance on Linux.
>
> Why?

It's not an easy question, do you have more information about the test
environment setup, and the statistics of the results?

I'd recommend using some analysis tools like DTrace to check what it's busy for.

Li-Wen