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From:Eric Bergen Date:January 15 2006 8:09am
Subject:Re: key_buffer_size vs innodb_buffer_pool_size
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The difference in recommendation size comes from the different
techniques each storage engine uses for caching data. myisam
(key_buffer_size) only stores indexes where innodb_buffer_pool_size
stores both indexes and data. mysiam relies on the operating system to
cache data in ram which is why you don't want to use all available
memory for the key buffer.

On 1/14/06, Grant Giddens <lggiddens@stripped> wrote:
> Hi,
>     After reading through the example my.cnf files (large, huge,  etc), I started to
> wonder what the difference was between the isam  key_buffer_size and the innodb
> innodb_buffer_pool_size.
>   I realize that they are two different table types, but some of the docs  says to
> set the key_buffer_size to 25%-50% of the overall system  memory.  The comments for the
> innodb_buffer_pool_size say that it  can be set to 50%-80% of the overall system memory.
>   Maybe I don't understand exactly the difference between the two because  I don't
> understand why they have different memory recommendations.
>   Is there any FAQs on the my.cnf file?  How would you set these two  variables if
> you had an even mix of isam and innodb tables?  Where  can I learn more about tweaking the
> my.cnf file?  The mysql online  documentation is good, but I need a more basic description
> of these two  variables and all the other my.cnf settings.
>   Thanks,
>   Grant
> ---------------------------------
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Eric Bergen
key_buffer_size vs innodb_buffer_pool_sizeGrant Giddens15 Jan
  • Re: key_buffer_size vs innodb_buffer_pool_sizeEric Bergen15 Jan
    • Re: key_buffer_size vs innodb_buffer_pool_sizeGrant Giddens17 Jan
      • Re: key_buffer_size vs innodb_buffer_pool_sizesheeri kritzer24 Jan