On Wed, Apr 25, 2012 at 3:06 PM, MB Software Solutions, LLC
<[email protected]> wrote:
> On 4/25/2012 10:01 AM, Ted Roche wrote:
>> Quantify, please: "I load 50 million rows of data and run a query that
>> should return 10 records and it takes 15 minutes." Or "I expect 25
>> million rows" in which case it should take 15 minutes! Or "It takes 7
>> seconds and I want it to take 5" -- these are different questions.

> Yes, and I thought I read you and the MySQL manual online earlier
> (http://dev.mysql.com/doc/refman/5.1/en/index-merge-optimization.html)
> to say that MySQL needs that compound index of the 3 fields to best
> optimize this query?!?  I thought that MySQL couldn't use all 3 separate
> single-field indexes and as such I wouldn't gain as much optimization.  ???
-------------------------------

You will get an index scan instead of an index seek.  Both of those
are much better than a table scan!



-- 
Stephen Russell
Sr. Analyst
Ring Container Technology
Oakland TN

901.246-0159 cell

_______________________________________________
Post Messages to: [email protected]
Subscription Maintenance: http://leafe.com/mailman/listinfo/profox
OT-free version of this list: http://leafe.com/mailman/listinfo/profoxtech
Searchable Archive: http://leafe.com/archives/search/profox
This message: 
http://leafe.com/archives/byMID/profox/cajidmyl3ot2zzyktrvknfckwp35-fs7rvosypi+u0xxmwpj...@mail.gmail.com
** All postings, unless explicitly stated otherwise, are the opinions of the 
author, and do not constitute legal or medical advice. This statement is added 
to the messages for those lawyers who are too stupid to see the obvious.

Reply via email to