Re: SP-GiST micro-optimizations

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: SP-GiST micro-optimizations
Дата
Msg-id 6524.1346179347@sss.pgh.pa.us
обсуждение исходный текст
Ответ на Re: SP-GiST micro-optimizations  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
Ответы Re: SP-GiST micro-optimizations
Список pgsql-hackers
Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> On 28.08.2012 20:30, Tom Lane wrote:
>> Fascinating.  I'd been of the opinion that modern compilers would inline
>> memset() for themselves and MemSet was probably not better than what the
>> compiler could do these days.  What platform are you testing on?

> x64, gcc 4.7.1, running Debian.

> The assembly generated for the MemSet is:
> [ pretty darn tight ]
> while the corresponding memset code is:
> [ not so good ]

Seems like that's down to the CPU not doing "rep stosq" particularly
quickly, which might well be chip-specific.

Anyway, IIRC there are similar memsets for all the SPGiST opclass
invocation calls, so I guess you should switch them all not just these
two.
        regards, tom lane



В списке pgsql-hackers по дате отправления:

Предыдущее
От: Robert Haas
Дата:
Сообщение: Re: MySQL search query is not executing in Postgres DB
Следующее
От: Tom Lane
Дата:
Сообщение: Re: MySQL search query is not executing in Postgres DB