In the last episode (Feb 24), Perrin Harkins said:
> On Wed, Feb 24, 2010 at 10:11 AM, Yang Zhang wrote:
> > Any ideas on how to optimize this by convincing mysql to see the
> > independence use a const join?
>
> http://www.xaprb.com/blog/2006/04/30/how-to-optimize-subqueries-and-joins-in-mysql/
You can use this to get rid of unused indicies too.
http://www.mysqlperformanceblog.com/2009/01/15/dropping-unused-indexes/
Requires the percona extensions to be loaded.
Cheers,
Andrew
-Original Message-
From: Andrew Braithwaite [mailto:andrew.braithwa...@lovefilm.com]
Sent: 24 Febru
There's also the Query Analyser
http://www.mysql.com/products/enterprise/query.html which is part of
MySQL Enterprise - I've never used it and it is very expensive but I
believe it will advise on optimal indicies.
Cheers,
Andrew
-Original Message-
From: Cantwell, Bryan [mailto:bcantw...@
On Wed, Feb 24, 2010 at 10:11 AM, Yang Zhang wrote:
> Any ideas on
> how to optimize this by convincing mysql to see the independence use a
> const join?
http://www.xaprb.com/blog/2006/04/30/how-to-optimize-subqueries-and-joins-in-mysql/
You need to rewrite as a join or use a FROM subquery. You
I have the following query. Note that the nested query has no
dependencies on the outer one, yet mysql reports it as dependent.
Furthermore, it says the join type is an ALL (nested loop join, the
slowest possible one, in which each row of the outer table results in
a complete inner table scan), whe
