Jim Kellerman wrote:
-----Original Message-----
From: Andrzej Bialecki [mailto:[EMAIL PROTECTED]
Sent: Monday, October 22, 2007 11:45 AM
To: [email protected]
Subject: HBase Bloom filters hash
Hi,
I'm curious why the hashing function that these filters use
is based on SHA-1 (which is relatively slow to compute)
instead of a bunch of fast and simple non-cryptographic
functions such as Jenkins' hash (see
http://bretm.home.comcast.net/hash/7.html
for the evaluation of Jenkins hash).
The reason for SHA-1 is that it was what came with the open
source bloom filter implementation we used. We've been focused
on just getting things to work and not on performance, yet.
If you'd like to open a Jira, it will be on the list of things
to do - sometime. If this is really important to you, how about
submitting a patch? There's mostly just the two of us, +
contributors, so we have to put our priorities on bug fixing
and making HBase robust before we get around to adding more
features or doing performance analysis.
We'd really like to get more contributions... the project would
mature much more rapidly.
That's perfectly understandable. I'm still in the discovery phase, and
it was something that caught my eye. I agree, it's a relatively low
priotity - I happen to have a Jenkins hash impl. in Java, if I find some
free time I'll prepare a patch.
--
Best regards,
Andrzej Bialecki <><
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