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From:Jeremy Zawodny Date:September 30 2003 5:22pm
Subject:Re: What are the effects of key_buffer on a dedicated slave
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On Tue, Sep 30, 2003 at 10:10:29AM -0700, Dathan Vance Pattishall wrote:
> I haven't notice a gain from increasing the key_buffer on a dedicated
> slave. Let's take 3.23.5x for instance. Since there is only 1 thread for
> replication, a Serialized committal of data, I wouldn't imagine that
> key_buffer at higher levels say around 50% of system memory would give a
> performance boost.

Is that all your slave is doing?  Replicating from the master?  Are there
no other queries being run against it?

> Is this observation wrong? Does raising key_buffer on a slave to around
> 50% of the memory available make a difference?

That depends, of course.  If your key_buffer is already twice the size
of all your MYI files, it won't make any difference.  Without knowing
the size of your index files, memory configuration, and the diversity
of key values needed in a short amount of time, it's impossible to say.

Jeremy
-- 
Jeremy D. Zawodny     |  Perl, Web, MySQL, Linux Magazine, Yahoo!
<Jeremy@stripped>  |  http://jeremy.zawodny.com/

MySQL 4.0.15-Yahoo-SMP: up 16 days, processed 586,089,594 queries (405/sec. avg)
Thread
What are the effects of key_buffer on a dedicated slaveDathan Vance Pattishall30 Sep
  • Re: What are the effects of key_buffer on a dedicated slaveJeremy Zawodny30 Sep
    • RE: What are the effects of key_buffer on a dedicated slaveDathan Vance Pattishall30 Sep
    • RE: What are the effects of key_buffer on a dedicated slave [also]Dathan Vance Pattishall30 Sep
      • Re: What are the effects of key_buffer on a dedicated slave [also]Jeremy Zawodny30 Sep
        • RE: What are the effects of key_buffer on a dedicated slave [also]Dathan Vance Pattishall30 Sep
          • Re: What are the effects of key_buffer on a dedicated slave [also]Jeremy Zawodny30 Sep
            • RE: What are the effects of key_buffer on a dedicated slave [also]Dathan Vance Pattishall30 Sep
              • Re: What are the effects of key_buffer on a dedicated slave [also]Jeremy Zawodny30 Sep
                • Re: What are the effects of key_buffer on a dedicated slave [also]William R. Mussatto30 Sep
                  • Re: What are the effects of key_buffer on a dedicated slave [also]Jeremy Zawodny1 Oct
  • Re: What are the effects of key_buffer on a dedicated slaveDan Nelson30 Sep
    • RE: What are the effects of key_buffer on a dedicated slaveDathan Vance Pattishall30 Sep