At Tag1 Consulting we do a lot of work on increasing web site performance, especially around Drupal sites. One of the common tools we use is memcached combined with the Drupal Memcache module. In Drupal, there are a number of different caches which are stored in the (typically MySQL) database by default. This is good for performance as it cuts down on potentially large/slow SQL queries and PHP execution needed to display content on a site.

read more