[TYPO3-core] RFC: #11271: Use 2 level cache for BEgetRootLine

[Steffen Kamper]

Hi,

Rupert Germann schrieb:
> when I made the patch to connect the treelist-cache to the caching framework
> I first made it the easy way by simply using the cache_hash table for tree
> lists, too. 
> Then I "devlogged" the actual amount of cache gets and sets in this table
> when rendering pages in FE and found that 20 queries to the treelist cache
> (for an uncached page) are not that uncommon.
> So I decided to stay with a seperate table and initialize an own cache for
> this.
> every additional function putting load on the caching framework should be
> benchmarked somehow before actually adding it to the code. 
> 

my intention was the same, as the function does a lot of recursiv SQL 
queries. As fist level cache was implemented it's called only one per 
session, but if you don't change/update pages it's processed on every BE 
request again.

It's quite obvious that reading one cache entry is much faster than a 
loop containing complex SQL.

For sure as Masi mentioned there has to be a "clear" mechanism in 
tcemain, but before hacking this in it would be good to have a general 
strategy for doing this, means "Clear which identifiers after 
create/move/delete/update".

vg Steffen