List:General Discussion« Previous MessageNext Message »
From:Baron Schwartz Date:May 26 2010 2:34am
Subject:Re: Innodb buffer pool size
View as plain text  

I'm going to disagree strongly with the previous advice you got.  You
should NOT configure the buffer pool to be larger than the amount of
RAM you have.  If part of the buffer pool is swapped out, then
swapping it back in is MUCH worse than re-fetching the page.  InnoDB
doesn't know the difference between in-memory and swapped out.
(That's the point of virtual memory; it's invisible to the program.)
It assumes that a "memory access" is fast.  If it turns out not to
really be a memory access, but instead is a disk access to swap
something in, then everything goes very badly.

If you search for "buffer pool size" on, you
will get good advice.  You should also get a copy of High Performance
MySQL, Second Edition.  (I'm the lead author.)  In short: ignore
advice about ratios, and ignore advice about the size of your data.
Configure the buffer pool to use the amount of memory available,
subtracting what's required for the OS and other things on the
computer to run effectively.

- Baron
Innodb buffer pool sizeMachiel Richards20 May
  • Re: Innodb buffer pool sizeNitin Mehta20 May
    • Re: Innodb buffer pool sizemachielr20 May
  • Re: Innodb buffer pool sizeRaj Shekhar21 May
  • Re: Innodb buffer pool sizeBaron Schwartz26 May