MySQL Bugs: #49852: make innodb checksum faster

Bug #49852	make innodb checksum faster
Submitted:	21 Dec 2009 17:43	Modified:	14 Oct 2011 17:34
Reporter:	Mark Callaghan	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: InnoDB Plugin storage engine	Severity:	S4 (Feature request)
Version:	5.0,5.1,5.1 plugin	OS:	Any
Assigned to:	Calvin Sun	CPU Architecture:	Any
Tags:	checksum, innodb, performance

Description:
I want an option to use a faster checksum algorithm for InnoDB. Justification for this is at http://www.facebook.com/note.php?note_id=217758745932.

As this requires a dump/reload, it should be done when the next InnoDB file format is added and possibly an option before then.

More details on this are at:
http://mysqlha.blogspot.com/2009/05/innodb-checksum-performance.html
http://mituzas.lt/2009/05/28/checksums-again-some-io-too/

How to repeat:
Run sysbench as described in the facebook note

Suggested fix:
compute the checksum one word at a time

Thank you for the feature request.

Added to 5.6.3 changelog:

You can improve the efficiency of the InnoDB checksum feature by
 specifying the configuration option innodb_checksum_algorithm=crc32,
 which turns on a faster checksum algorithm. This option replaces the
 innodb_checksums option. Data written using the old checksum
 algorithm (option value innodb) is fully upward-compatible;
 tablespaces modified using the new checksum algorithm (option value
 crc32) cannot be downgraded to an earlier version of MySQL that does
 not support the innodb_checksum_algorithm option. See for details.