List:General Discussion« Previous MessageNext Message »
From:mos Date:November 24 2009 4:22pm
Subject:Re: How normal mysql server 5.1 uses multiple cores
View as plain text  
At 06:44 AM 11/24/2009, you wrote:
>2009/11/24 Johan De Meersman <vegivamp@stripped>:
> > If you are wondering about parallel query execution (that is, splitting a
> > single query over multiple cores for faster execution), that is currently
> > not supported by MySQL.
>
>[offtopic]
>Probably is something stupid, but could that be done with ndb cluster
>on a single host? Anyway, I suppose performance loses on distributed
>joins and so on would outcome multiple-core benefits. And for most
>queries, the bottleneck is usually on disk access, not processor. Has
>anybody done any serious testing on this?

Jaime,
        Well it all depends on the SQL that is being executed, the table 
structure and the size of the query. Now for a particular case you can do 
your own benchmarking quite easily to see if disk speed is more relevant 
than CPU speed. Copy your tables into a MEMORY table and do the joins 
there. Compare that to a disk join (reset the query cache) and see the 
improvement.  I'm guessing you will probably see a 300% improvement over 
disk. As mentioned earlier, MySQL does not scale up very well with multiple 
processors which is why it is better to scale out horizontally with clusters.

Mike 

Thread
How normal mysql server 5.1 uses multiple coresManasi Save24 Nov
  • Re: How normal mysql server 5.1 uses multiple coresJohan De Meersman24 Nov
    • Re: How normal mysql server 5.1 uses multiple coresManasi Save24 Nov
      • Re: How normal mysql server 5.1 uses multiple coresJohan De Meersman24 Nov
    • Re: How normal mysql server 5.1 uses multiple coresJaime Crespo Rinc√≥n24 Nov
      • Re: How normal mysql server 5.1 uses multiple coresmos24 Nov