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From:Sasha Pachev Date:April 2 1999 5:17pm
Subject:Re: powers of two in my.cnf ?
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Michael Widenius wrote:
> >>>>> "matthew" == matthew mcglynn <mcglynn@stripped> writes:
> matthew> This is probably a really dumb question...
> matthew> Every example of buffer settings I've seen
> matthew> has used powers of two. For example, from the
> matthew> sample configuration file:
> matthew> set-variable    = key_buffer=16M
> matthew> set-variable    = max_allowed_packet=1M
> matthew> set-variable    = thread_stack=128K
> matthew> set-variable    = max_allowed_packet=16M
> matthew> set-variable    = keybuffer=16M
> matthew> Similarly, the default table_cache is 64, and when
> matthew> people ask on this list about running out of file
> matthew> descriptors, the response is usually "set table_cache
> matthew> to 32".
> matthew> My dumb question is: do these have to all be powers of two ?!
> matthew> If for my application, a table_cache of 128 is insufficient,
> matthew> can I bump it to 150 or do I need to go all the way to 256 ?
> Hi!
> I just prefer to use powers as two as this gives you the best memory
> utilization with many memory allocation packages!
> You don't however have to use powers of two;  For the table cache 150
> should be fine!
> Regards,
> Monty

And to add to what Monty has said, powers of 2 are
"holy" numbers for a programmer, just like powers of 10
are "holy" for non-programmers. 

Sasha Pachev (home) (work)
powers of two in my.cnf ?matthew mcglynn2 Apr
  • powers of two in my.cnf ?Michael Widenius2 Apr
  • Re: powers of two in my.cnf ?Sasha Pachev2 Apr
Re: powers of two in my.cnf ?jkraai2 Apr