Moving a WordPress database from one domain to another can be quite aÂ challengingÂ task. If you would like to move a copy of a WordPress database from a production environment to a local development environment for example, you would probably like to change the domain names used in that database.
WordPress (currently 3.5.1) limits the memory usage to 32M for single-site installations and 64M for multi-site installations on the front-end. In the back-end it is set to 256M (if possible) by default. This is done in the PHP-code, it means that your current web server setup needs to allow setting php.ini variables from code.