MySQL Bugs: #20449: Information about ANALYZE of InnoDB tables is missing

Bug #20449	Information about ANALYZE of InnoDB tables is missing
Submitted:	14 Jun 2006 7:38	Modified:	20 Jun 2006 13:47
Reporter:	Oli Sennhauser	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Documentation	Severity:	S3 (Non-critical)
Version:	5.0	OS:	n.a.
Assigned to:	MC Brown	CPU Architecture:	Any

Description:
Information about ANALYZE of InnoDB tables is partially wrong, missing and/or incomplete.

How to repeat:
13.5.2.1. ANALYZE TABLE Syntax
http://dev.mysql.com/doc/refman/5.0/en/analyze-table.html

"During the analysis, the table is locked with a read lock." ==> This is NOT valid for InnoDB.

I found in the InnoDB documentation some text which describes the ANALYZE for InnoDB as follows:
"It makes 10 random dives to each of the index trees and updates index cardinality estimates accordingly. Note that since it is only an estimate, repeated runs of ANALYZE TABLE may produce different numbers. MySQL uses index cardinality estimates only in join optimization. If some join is not optimized in the right way, you may try using ANALYZE TABLE."

Suggested fix:
See above.

Thank you for a reasonable documentation request.

This has been addressed in the 4.1, 5.0 and 5.1 manuals. 

I've added a note that InnoDB ANALYZE is write-lock, not read. The additional info about how InnoDB actually does an ANAYLYZE already exists in the InnoDB docs, so I've added a link from the ANALYZE TABLE page to the corresponding area in the InnoDB documentation.