since year 2008 there comes a new module called cacherouter. which is born from the following module/projects: APC, fastpath_fscache, Memcache, and XCache.

beside general enabling the module, there is a configure step has to be done.
Installation
1. Enable the module in admin/build/modules.
2. Setup your settings.php

this module is avaliable for drupal 5.x and 6.x at http://drupal.org/project/cacherouter

it works on large database(gigabytes) and very flexible.

backup command:
mysqldump -h localhost -u mydbusername -p mydbname >mydbbackupfile_dateoftoday.sql

restore command:
mysql -u mydbusername -p mydbtarget < mydbbackupfile_dateoftoday.sql

example:
backup command:
mysqldump -u root -p db1 >db1_bak_20050703.sql

restore command:
mysql -u root -p db1 < db1_bak_20050703.sql