Re: Single client performance on trivial SELECTs - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Single client performance on trivial SELECTs
Date
Msg-id 20664.1302815441@sss.pgh.pa.us
Whole thread Raw
In response to Re: Single client performance on trivial SELECTs  (Noah Misch <noah@leadboat.com>)
Responses Re: Single client performance on trivial SELECTs  (Merlin Moncure <mmoncure@gmail.com>)
Re: Single client performance on trivial SELECTs  (Andres Freund <andres@anarazel.de>)
Re: Single client performance on trivial SELECTs  (Noah Misch <noah@leadboat.com>)
List pgsql-hackers
Noah Misch <noah@leadboat.com> writes:
> On Thu, Apr 14, 2011 at 11:15:00AM -0700, Robert Haas wrote:
>> It shouldn't be
>> terribly difficult to come up with some kind of hash function based
>> on, say, the first two characters of the keyword that would be a lot
>> faster than what we're doing now.

> I'd look at `gperf', which generates code for this from your keyword list.

FWIW, mysql used to use gperf for this purpose, but they've abandoned it
in favor of some homegrown hashing scheme.  I don't know exactly why,
but I wonder if it was for licensing reasons.  gperf itself is GPL, and
I don't see any disclaimer in the docs saying that its output isn't.
        regards, tom lane


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