PHP and MySQL — I bet this sounds very familiar to you. If you have a blog, a WordPress blog, a Drupal, or a Joomla website, you use both PHP and MySQL as the technology to serve your content management. PHP: Hypertext Preprocessor is a widely used, general-purpose scripting language that was originally designed for web development to produce dynamic web pages. And MySQL is a relational database management system (RDBMS) that runs as a server providing multi-user access to a number of databases.
PHP development began in 1994 and MySQL development began in 1994 too. After a while these two products are widely used together, along with Apache as the web server. The final version of PHP 4 was released during August of 2008, followed by the final version of MySQL 4 in December of 2008. Both PHP 4 and MySQL 4 have been discontinued for almost two years. So the technology and security behind PHP 4 and MySQL 4 is far behind PHP 5 and MySQL 5.
WordPress already announced they will end their support for PHP 4 and MySQL 4. You can read their announcement on their blog post here. And as you know, Drupal and Joomla have already done the same thing this year. From the WordPress data, only 11% of WordPress blogs are running under PHP 5.2. And they are very clear about their next release: WordPress 3.2 won’t support PHP 4 and MySQL 4 anymore. Thus WordPress 3.1 (to be released at the end of 2010) will be the last WordPress that supports PHP 4 and MySQL 4.
After this announcement I think PHP 4 and MySQL 4 will no longer be used. So is your hosting provider still using PHP 4 and MySQL 4? If so, ask them to upgrade or move to another host.