When APC appears to fail Drupal

There are quite a large number of resources on the internet that exist due to the error that springs up on Drupal sites with APC enabled: Cannot redeclare class insertquery_mysql in /path/to/drupal/includes/database/database.inc on line 1774.Whilst many of them provide work arounds like…

Too much caching to code

Traditionally, and sensibly, one develops a site before attempting to optimise the server. The reason behind this being that simple changes to the site (modules or themes) that would require a page refresh to take effect could end up requiring either a site cache clear or even an Apache/PHP…