Monthly Archives - June 2006

What MySQL buffer cache hit rate should you target

“What cache hit rate is good for optimal MySQL Performance” is typical question I’m asked. It could by MyISAM key_buffer or Innodb innodb_buffer_pool it does not really matter. In both cases trying to come up with constant “good” hit rate is looking for trouble. Well of course you can name 100% hit […]

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FreeBSD tests

I’m continuing my experiments with different OS and today I tested FreeBSD 6.0 on my box.
(more details about box and benchmark see here https://www.percona.com/blog/2006/06/13/quick-look-at-ubuntu-606/).
Initially I was very pessimistic about FreeBSD, as results were (in transactions/sec, more is better.
for comparison the results from Suse 10.0):

InnoDB

threads
FreeBSD 6
Suse 10.0
Suse/ FreeBSD ratio

1
436.97
536.91
1.23

4
322.08
816.27
2.53

16
519.94
639.05
1.23

64
crash
547.07

256

357.09

MyISAM

threads
FreeBSD 6
Suse 10.0
Suse/ FreeBSD ratio

1
335.56
429.89
1.28

4
165.16
863.23
5.23

16
322.66
537.67
1.67

64
crash
516.00

256

346.65

The crash with […]

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MyISAM concurrent insert

Arjen posted a good note about MyISAM concurrent-insert features, though I should mention concurrent-insert can be cause of
scalablity and peformance problems on SMP boxes, especially on queries processing range-queries. The reason of problems is POSIX read-write locks, which are used to protect key_buffer from concurrent changes and called for each processed row. More info […]

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Why MySQL could be slow with large tables ?

If you’ve been reading enough database related forums, mailing lists or blogs you probably heard complains about MySQL being unable to handle more than 1,000,000 (or select any other number) rows by some of the users. On other hand it is well known with customers like Google, Yahoo, LiveJournal,Technocarati MySQL has installations with many […]

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