Kaare Rasmussen <kar@webline.dk> wrote:
> I think a bit of explanation is required for this story:
>
> http://www.newsalert.com/bin/story?StoryId=CozDUWbKbytiXnZy&FQ=Linux&Nav=na-search-&StoryTitle=Linux
>
> Up until now, the MySQL people have been boasting performance as the
> product's great advantage. Now this contradicts thi sfor the first time. I
> believe it has to do with the test. Perhaps MySQL is faster when you just
> do one simple SELECT * FROM table, and that it has never really been
> tested in a real-life (or as close as possible) environment?
I wouldn't say that this is exactly the first time we've heard
about problems with MySQL's famed "speed". Take the Tim Perdue
article that came out a while back:
http://www.phpbuilder.com/columns/tim20000705.php3?page=1
The most interesting thing about my test results was to see how much of a load Postgres could withstand before
givingany errors. In fact, Postgres seemed to scale 3 times higher than MySQL before giving any errors at all. MySQL
beginscollapsing at about 40-50 concurrent connections, whereas Postgres handily scaled to 120 before balking. My
guessis, that Postgres could have gone far past 120 connections with enough memory and CPU.
On the surface, this can appear to be a huge win for Postgres, but if you look at the results in more detail,
you'llsee that Postgres took up to 2-3 times longer to generate each page, so it needs to scale 2-3 times higher just
tobreak even with MySQL. So in terms of max numbers of pages generated concurrently without giving errors, it's
prettymuch a dead heat between the two databases. In terms of generating one page at a time, MySQL does it up to 2-3
timesfaster.
As written, this not exactly slanted toward postgresql, but
you could easily rephrase this as "MySQL is fast, but not
under heavy load. When heavily loaded, it degrades much
faster than Postgresql, and they're both roughly the same
speed, despite the fact that postgresql is doing more
(transaction processing, etc.)."
This story has made slashdot:
http://slashdot.org/article.pl?sid=00/08/14/2128237&mode=nested
Some of the comments are interesting. One MySQL defender
claims that the bottle neck in the benchmarks Great Bridge
used is the ODBC drivers. It's possible that all the test
really shows is that MySQL has a poor ODBC driver.