Mediawiki purge cache on ALL files
To clear the cache for all files on a MediaWiki, you need shell access.
Add $wgInvalidateCacheOnLocalSettingsChange = true;
and
$wgEnableParserCache = true;
to/path-to-wiki/wiki/LocalSettings.php
Using a text edit such as vim, open /path-to-wiki/wiki/LocalSettings.php and save it. This effectively clears the cache timestamp so any file edited prior to LocalSettings.php timestamp are re-fetched and not taken from the cache.
The unix command touch /path-to-wiki/wiki/LocalSettings.php would have the same effect.
MediaWiki Namespaces
A bit of lazy cut and paste to show the purpose of each namespace:
'0' => '(articles)',
'1' => 'Talk:',
'2' => 'User:',
'3' => 'User_talk:',
'4' => 'Project',
'5' => 'Project_talk:',
'6' => 'File:',
'7' => 'File_talk',
'8' => 'MediaWiki:',
'9' => 'MediaWiki_talk:',
'10' => 'Template:',
'11' => 'Template_talk:',
'12' => 'Help:',
'13' => 'Help_talk:',
'14' => 'Category:',
'15' => 'Category_talk:',
MediaWiki - Clear the cache of a single page
To clear the cache on an individual page on a MediaWiki the easy way is to click the view-history link, delete the word history and replace with purge, eg:
from
http://www.is-beer-a-vegetable.com/wiki/index.php?title=Mediawiki_purge_cache_on_ALL_files&action=history
to
http://www.is-beer-a-vegetable.com/wiki/index.php?title=Mediawiki_purge_cache_on_ALL_files&action=purge
Removing Mediawiki cache table to save space
On a busy Wikis, I've had the table 'objectcache' up to 5 gb in size. This caused massive processor load while the tables were being compressed and archived. The table objectcache can be safely deleted without any problems:
Objectcache table is used for a few generic cache operations if not using Memcached. Its content can be deleted and excluded from backups as it will be regenerated when needed. from manual:objectcache table