[TYPO3-core] RFC: #11285: functions flushByTag and flushByTags in caching framework are very unefficient

[Rupert Germann]

Hi,

This is an SVN patch request.

Type: 
major perfomance issue

Bugtracker references:
http://bugs.typo3.org/view.php?id=11285

Branches:
trunk

Problem:
functions flushByTag() and flushByTags() in caching framework db backend are
very processing intensive because they do multiple(!) loops to clean the
cache entries one by one. This can lead to performance issues in the
BackEnd when changing parts of a huge pagetree.

Solution:
use one mysql query per function that cleans all entries with the requested
tags at once. 

greets
rupert