Bug #2506 select_full_joins is increased without query execution
Submitted: 25 Jan 2004 14:19 Modified: 4 Feb 2004 16:32
Reporter: Peter Zaitsev (Basic Quality Contributor) Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server Severity:S3 (Non-critical)
Version:4.0.17 OS:Any (all)
Assigned to: Michael Widenius CPU Architecture:Any

[25 Jan 2004 14:19] Peter Zaitsev 
Description:
"select_full_joins" variable is increased when EXPLAIN is called for such query,
which should not happen as results in false alerts.

It is good practice to run EXPLAIN for your queries to make sure they are not "full_joins" :)

How to repeat:
EXPLAIN SELECT * from tbl, tbl t;

(Actually any "full join" query will work. 

Suggested fix:
Perhaps we need to check for describe flag incrementing this variable ?
[4 Feb 2004 16:32] Michael Widenius 
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
    http://www.mysql.com/doc/en/Installing_source_tree.html

Additional info:

Fix will be in 4.0.18 and 4.1.2