Optimizing MySQL: Hardware and the Mysqld Variables

December 17, 2001

Part 1 - Compiling MySQL

Like a grand prix driver starting at the back of the track, if you don't do things well from the beginning, and prepare hard for the race, it doesn't matter how well you do once the race has started. You're at the back and are never going to win. So, with MySQL, it's extremely important to start off on the right foot, and that means compiling MySQL properly. The specific options you use depends on your setup of course, but here are some pointers to get you started.

• Firstly, compile statically (--static). This requires more disk space, but runs faster (13% on Linux, according to MySQL themselves)
• Optimize to the highest level possible (-O3 with gcc)
• Compile without debug (--without-debug). This runs 20-35% faster.
• Compile without frame pointers. (-fomit-frame-pointer). This is from 1-4% faster.
• Compile with only the minimum character sets that you need (e.g. --with-extra- charsets=none)

Here's a sample configuration I've seen work well:

	CFLAGS="-mcpu=i686 -march=i686 -O3 -pipe -fomit-frame-pointer" \
./configure \
        --prefix=/usr/local/build/mysql \
        --with-mysqld-user=mysql \
        --without-debug \
        --with-client-ldflags=-all-static \
        --with-mysqld-ldflags=-all-static \
        --disable-shared \
        --localstatedir=/usr/local/build/mysql/var \
        --with-extra-charsets=none \
        --enable-assembler

Note that if you're using a Pentium processor, using pgcc seems to give better results than gcc. There have been problems with pgcc and AMD processors though. For a list of complete gcc options, run:

man gcc

Taking the time to compile as well as possible for your setup is worth it. After all, you'll probably only do this once, but it can hamstring your server for life if you get it wrong (it's not fun recompiling after your server is setup and running!)