Bug #83750 Import via TTS of a partitioned table only uses 1 cpu core
Submitted: 8 Nov 2016 22:19 Modified: 23 Aug 2017 13:01
Reporter: Daniël van Eeden (OCA) Email Updates:
Status: Verified Impact on me:
Category:MySQL Server: InnoDB storage engine Severity:S4 (Feature request)
Version:5.7.15, 5.7.19 OS:Any
Assigned to: CPU Architecture:Any
Tags: compression, innodb, parallel, performance, tts

[8 Nov 2016 22:19] Daniël van Eeden
ALTER TABLE x IMPORT TABLESPACE of a partitioned table only uses 1 CPU core.

How to repeat:
Import a partitioned InnoDB table and check CPU usage.

Suggested fix:
It should try to use multiple CPU cores and do the work in parallel.
[9 Nov 2016 8:04] Daniël van Eeden
ALTER TABLE x IMPORT TABLESPACE took 1 hour 48 min for compressed (key_block_size=8) table with 64 partitions and about 520G of ibd files.

It only used one CPU core.

I guess importing 64 tables and then using ALTER TABLE x EXCHANGE PARTITION.. would have been much faster, but that doesn't work with all partitioning types
[10 Jan 2017 15:08] Sinisa Milivojevic

I find that this is truly a very sensible request, since this is one area where improvement in performance is necessary.  Hence, I am verifying it as a feature request.

Thank you.
[23 Aug 2017 13:00] Daniël van Eeden
mysql_upgrade runs "REPAIR NO_WRITE_TO_BINLOG TABLE <table>" .. and only uses 1 cpu core. This is also a partitioned table and very CPU bound.
[23 Aug 2017 13:01] Daniël van Eeden
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