Re: [PATCH] backend: compare word-at-a-time in bcTruelen

Поиск
Список
Период
Сортировка
От Jeremy Kerr
Тема Re: [PATCH] backend: compare word-at-a-time in bcTruelen
Дата
Msg-id 200906171731.07149.jk@ozlabs.org
обсуждение исходный текст
Ответ на Re: [PATCH] backend: compare word-at-a-time in bcTruelen  (Tom Lane <tgl@sss.pgh.pa.us>)
Ответы Re: [PATCH] backend: compare word-at-a-time in bcTruelen  (Gurjeet Singh <singh.gurjeet@gmail.com>)
Re: [PATCH] backend: compare word-at-a-time in bcTruelen  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
Re: [PATCH] backend: compare word-at-a-time in bcTruelen  (Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>)
[PATCH] backend: compare word-at-a-time in bcTruelen  (Jeremy Kerr <jk@ozlabs.org>)
Список pgsql-hackers
Hi all,

> 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.

Will re-send the patch once I work out how to get git to create a 
context diff...

Cheers,


Jeremy



В списке pgsql-hackers по дате отправления:

Предыдущее
От: Petr Jelinek
Дата:
Сообщение: Re: GRANT ON ALL IN schema
Следующее
От: Gurjeet Singh
Дата:
Сообщение: Re: [PATCH] backend: compare word-at-a-time in bcTruelen