Details
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Task
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Status: Closed (View Workflow)
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Major
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Resolution: Fixed
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None
Description
In order to make an educated decision to drop the change buffer, benchmark suitable workloads and check effect of change buffer turned on vs. off.
Attachments
Issue Links
- relates to
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MDEV-515 innodb bulk insert
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- Closed
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MDEV-11634 Improve the InnoDB change buffer
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- Closed
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I did a benchmark with 10.2.9 and sysbench OLTP write-only. The workload is 18 updates per transaction, changing the value of an indexed column. I have 3 result sets, restricting the size of the change buffer to 25% (default), 50% and 0% (aka turned off) of the buffer pool.
Numbers (transactions per second, bigger=better)
threads 25% 50% 0%
1 436.93 454.15 414.97
2 1128.5 1108.0 1072.1
4 2179.0 2152.6 2256.9
8 4353.1 4355.5 4169.6
16 7659.4 7623.6 7181.1
32 10250 10415 10317
64 11032 11139 10782
128 11447 11543 11104
256 11424 11452 11161
Conclusion: turning off the change buffer does affect performance, mostly for light to medium load.