| From: | Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> |
|---|---|
| To: | Jeremy Kerr <jk(at)ozlabs(dot)org> |
| Cc: | pgsql-hackers(at)postgresql(dot)org, Stephen Frost <sfrost(at)snowman(dot)net>, Robert Haas <robertmhaas(at)gmail(dot)com>, Alvaro Herrera <alvherre(at)commandprompt(dot)com>, Stefan Kaltenbrunner <stefan(at)kaltenbrunner(dot)cc>, Gurjeet Singh <singh(dot)gurjeet(at)gmail(dot)com> |
| Subject: | Re: [PATCH] backend: compare word-at-a-time in bcTruelen |
| Date: | 2009-06-17 09:51:29 |
| Message-ID: | 4A38BCA1.1020701@enterprisedb.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Jeremy Kerr wrote:
>> Speaking of which, what about some performance numbers?
>
> OK, benchmarks done:
>
> http://ozlabs.org/~jk/projects/db/data/postgres.bcTruelen/
>
> Summary: small increase in performance (~1-2% on my machine), at about
> 1.5 standard deviations from the mean. Profiles show a decent drop in
> hits within bcTruelen.
>
> However: Sysbench seems to be quite heavy with the fixed-width char
> types, so may end up calling bcTruelen more than most workloads. Would
> be nice to get some x86 numbers too, but I don't have a suitable machine
> here.
>
> So: The increase in performance is positive on this workload, albeit
> fairly minor. Downside is increased code complexity.
Based on this benchmark, I don't think this patch is worth it..
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Gurjeet Singh | 2009-06-17 10:00:25 | Re: [PATCH] backend: compare word-at-a-time in bcTruelen |
| Previous Message | Gurjeet Singh | 2009-06-17 09:42:12 | Re: [PATCH] backend: compare word-at-a-time in bcTruelen |