[TYPO3-core] RFC: Bug #11903: Use separate tables for tags in the caching framework

[Oliver Hader]

This is an SVN patch request.

Type: Bugfix / database modification

Bugtracker references:
http://bugs.typo3.org/view.php?id=11903

Branch: Trunk

Problem:
The database backend of the caching framework stores tags in a comma
separated list. Searching for tags results in a LIKE query which will be
very slow when there are many cache entries.

Solution:
Use separate tables to store tags and optimize the queries to prevent
full table scans. Besides that the identifiers have been reduced to 128
chars - that should be enough.

Notes:
Due to #11505 you have to enable the caching framework in the install
tool if you want to test this issue.

In TYPO3_DB an new method was introduced: exec_DELETEmultipleTablesQuery
This method currently is not covered by DBAL since it would be difficult
to use a common query here. However, Xavier as DBAL leader is informed.
We can fix this remaining issue until TYPO3 4.3 RC.

olly
-- 
Oliver Hader
TYPO3 Release Manager 4.3