[TYPO3-dev] Typo3 Performance

[Dmitry Dulepov]

John Angel wrote:
>> Let's begin and remove those pointless indices suggested on the page. 
>> With
>> indices it's like RAM, they are not the solution for everything.
>> Furthermore they must be crafted carefully to be used at all when
>> required.
> 
> I agree, we've mentioned that already, let's see what should be 
> optimized carefully.
> 
> Some discussion was in bug:
> http://bugs.typo3.org/view.php?id=4875

Those indexes are not really correct. Look:
---------
ALTER TABLE `be_groups` ADD INDEX ( `deleted` ( 1 ) ) ;
ALTER TABLE `be_groups` ADD INDEX ( `hidden` ( 1 ) ) ;
---------

So mysql will use either deleted or hidden index, he will not use both! 
Much better will be:

ALTER TABLE `be_groups` ADD INDEX (`deleted`, `hidden`)

and in the order of the query (mysql is clever sometimes to understand 
that he can use index with another order but sometimes it still ignores 
it). Same for others. Indexes, as they defined in the bug, will help but 
they could be much better.

There is a good book named "high performance mysql" that explains a lot 
about correct index usage. It is written by a guy, who created mysql 
servers' setup for Yahoo.

-- 
Dmitry Dulepov

Web: http://typo3bloke.net/
Skype: callto:liels_bugs

"It is our choices, that show what we truly are,
far more than our abilities." (A.P.W.B.D.)