MySQL often is the bottle neck in a webserver configuration. It is essential that MySQL thefore is up to date. Here an easy way to accomplish this with Debian soure packages.
Quick code overview to compile a debian mysql5 server package, and to install it.
apt-get install libdbi-perl libdbd-mysql-perl apt-get build-dep mysql-server apt-get -b source mysql-server dpkg -i mysql-common_..all.deb dpkg -i mysql-client-..i386.deb dpkg -i mysql-server-..i386.deb mysqladmin -u root password 'yourpassword'
It might also be required to integrate mysql functionality into php:
apt-get install php5-mysql
To access the mysql command line:
mysql -u root -pyourpassword