Bug #9824 REPAIR truncates tables with old checksum
Submitted: 11 Apr 2005 17:28 Modified: 1 Jun 2005 20:12
Reporter: Sergei Golubchik Email Updates:
Status: Closed Impact on me:
Category:MySQL Server: MyISAM storage engine Severity:S3 (Non-critical)
Version: OS:
Assigned to: Sergei Golubchik

[11 Apr 2005 17:28] Sergei Golubchik
In 4.1 checksum algorithm in MyISAM was changed.
As a result tables created in 4.0 that have live checksum enabled, appear corrupted in 4.1

The bug is that REPAIR TABLE extended or not, discards rows with incorrect checksum, effectively truncating the table to 0 rows.

Also, a manual should contain the note about it. In News-4.1.1 and Upgrading to 4.1

How to repeat:

Suggested fix:
[11 Apr 2005 18:40] Sergei Golubchik
Thank you for your bug report. This issue has been committed to our
source repository of that product and will be incorporated into the
next release.

If necessary, you can access the source repository and build the latest
available version, including the bugfix, yourself. More information 
about accessing the source trees is available at

Additional info:

Fixed in 4.1.12
[1 Jun 2005 15:00] [ name withheld ]
I am still experiencing this problem with 4.1.12.  The release notes for 4.1.12 do not mention this as a fixed bug.  Did the bug fix actually make it into the release?
[1 Jun 2005 20:12] Sergei Golubchik
It did. Please open a new  bugreport for your case, and don't
forget to provide a full repeatable test case.