Re: Re: CRC

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: Re: CRC
Дата
Msg-id 3457.976311058@sss.pgh.pa.us
обсуждение исходный текст
Ответ на Re: Re: CRC  (Bruce Guenter <bruceg@em.ca>)
Ответы Re: Re: CRC  (Bruce Guenter <bruceg@em.ca>)
Список pgsql-hackers
Bruce Guenter <bruceg@em.ca> writes:
>> Are you really saying MD5 was faster than CRC-32?

> Yes.  I expect it's because the operations used in MD5 are easily
> parallelized, and operate on blocks of 64-bytes at a time, while the CRC
> is mostly non-parallelizable, uses a table lookup, and operates on
> single bytes.

What MD5 implementation did you use?  The one I have handy (the original
RSA reference version) sure looks like it's more computation per byte
than a CRC.
        regards, tom lane


В списке pgsql-hackers по дате отправления:

Предыдущее
От: Tom Lane
Дата:
Сообщение: Re: Re: CRC
Следующее
От: Tom Lane
Дата:
Сообщение: Hash index on macaddr -> crash