Tag - InnoDB

Returning to InnoDB scalability

I’m again returning to InnoDB scalability and related bug #15815 as it hurts many users and customers using multi-cpu servers.
Short intro into problem:
On 4-CPU box 1 thread executes full-table scan select query for 8 sec,
but with 4 threads – each thread executes query for 240 sec.
It is very strange as threads use only SELECT […]

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INSERT INTO … SELECT Performance with Innodb tables.

Everyone using Innodb tables probably got use to the fact Innodb tables perform non locking reads, meaning unless you use some modifiers such as LOCK IN SHARE MODE or FOR UPDATE, SELECT statements will not lock any rows while running.
This is generally correct, however there a notable exception – INSERT […]

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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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