I have just upgraded MySQL 5.0 to Percona XtraDB 5.1. I had to yum remove all the mysql stuff first. Everything was working fine, until I restarted Apache and now I get:
Fatal error: Call to undefined function mysql_connect()
Any ideas? I have a feeling I removed some sort of mysql plugin for apache at the same time.
You need to install the php-mysql library. Depending on your distribution, this may have a slightly different name. Also, I was just experimenting with this on Ubuntu 11.04. Ended up going back to MySQL because PHP-MySQL wouldn't install without libmysqlcient16 which wouldn't install because it conflicted with percona. Hopefully, you don't run into the same problems that I did.