Bug #55753 CHECKSUM TABLE warning needs clarification

• Submitted: 5 Aug 2010 0:24
• Modified: 5 Aug 2010 10:42
• Reporter: Gary Pendergast
• Status: Closed
• Category: MySQL Server: Documentation
• Severity: S3 (Non-critical)
• Version: all
• OS: Any
• Assigned to: Jon Stephens
• CPU Architecture: Any
• Tags: checksum table

[5 Aug 2010 0:24] Gary Pendergast

Description:
http://dev.mysql.com/doc/refman/5.1/en/checksum-table.html

This documentation has the following warning:

If the checksums for two tables are different, then the tables are different in some way. However, the fact that two tables produce the same checksum does not mean that the tables are identical. 

How to repeat:
-

Suggested fix:
I think this could be clarified a little more to say that the latter is an unlikely scenario, and is caused by the Hash Collision problem, perhaps with a Wikipedia link for further reading?

http://en.wikipedia.org/wiki/Hash_collision

[5 Aug 2010 6:58] Jon Stephens

Since I wrote the bit in question, I'll take this bug.

[5 Aug 2010 10:26] MySQL Verification Team

take a peek at bug #39474 also... this isn't purely down to hash collisions....

[5 Aug 2010 10:42] Jon Stephens

I've amended the wording slightly. I'm reluctant to do more due about BUG#39474 (which bug report is the reason why the Important note was added in the first place).

Please discuss this with Shane if you've any more questions about this or BUG#39474.

cheers

jon.