| flush | 1 | Clears out all caches. Used mainly during development, e.g. when adding new classes or templates. Requires "dev" mode or ADMIN login |
| showtemplate | 1 | Show the compiled version of all the templates used, including line numbers. Good when you have a syntax error in a template. Cannot be used on a Live site without **isDev**. |
| isDev | 1 | Put the site into [development mode](../), enabling debugging messages to the browser on a live server. For security, you'll be asked to log in with an administrator log-in. Will persist for the current browser session. |
| isTest | 1 | See above. |
| debug | 1 | Show a collection of debugging information about the director / controller operation |
| debug_request | 1 | Show all steps of the request from initial [HTTPRequest](api:SilverStripe\Control\HTTPRequest) to [Controller](api:SilverStripe\Control\Controller) to Template Rendering |
| execmetric | 1 | Display the execution time and peak memory usage for the request |
| showqueries | 1 | inline | List all SQL queries executed, the `inline` option will do a fudge replacement of parameterised queries |
| showqueries | 1 | backtrace | List all SQL queries executed, the `backtrace` option will do a fudge replacement of parameterised queries *and* show a backtrace of every query |
| previewwrite | 1 | List all insert / update SQL queries, and **don't** execute them. Useful for previewing writes to the database. |