Bug #86071 query_rewrite should generate performance_schema counters on usage
Submitted: 25 Apr 2017 13:14 Modified: 9 Feb 2018 11:34
Reporter: Simon Mudd (OCA) Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Server: Parser Severity:S4 (Feature request)
Version:5.7, 8.0 OS:Any
Assigned to: CPU Architecture:Any
Tags: query_rewrite plugin

[25 Apr 2017 13:14] Simon Mudd 
Description:
I couldn't find a category for the query_rewrite plugin

The query rewrite plugin https://dev.mysql.com/doc/refman/5.7/en/rewriter-query-rewrite-plugin.html can be clearly useful for a number of situations.

Looking at the documentation however it seems that if you enable it there are no performance_schema counters or metrics which indicate the extra processing it took or the number of times the rules matched the matched the rules

How to repeat:
see above.

Suggested fix:
I think it would be convenient to have at least the following:
* counters of the number of rules matched
* counters of any errors or warnings such modified queries generated (it may be that a rewritten query does not parse so it would generate errors. Being able to see that might be useful)
[9 Feb 2018 11:34] MySQL Verification Team 
Hello Simon,

Thank you for the feature request.

Thanks,
Umesh