[TYPO3-english] Extbase -> reduce queries in m:m relations

[Robert Wildling]

Hi,

I have a kind of library extension that is really rich on m:m tables. It 
is actually an event extension used as retrospective on an event that 
took place once a year over the last 17 years. It contains event 
information, people's profiles, concert data, catalogue of works, 
location stuff etcetc, everything made with m:m relations, so a kind of 
"data mining" presentation of all the info is easily possible.

When calling the overview event table, the querying process lasts very, 
very long (something like 8 seconds on my local machine). There are only 
17 events, but around 20 m:m relations to tables that again have 
m:m-relations. Extbase's findAll() seems to read out *all* the 
information of all those m:m connected tables as the ViewHelper 
<f:debug> proves.

I know that there are functions like "->contains" and "->matching" to 
build individual queries, but they don't seem to allow to limit the 
amount of fields to be read, so they eventually again read out each and 
everything.

Or am I wrong? Is there any way to tell an extbase query to only read a 
very limited amount of fields from m:m-tables, even on the 3rd and 4th 
level? (subselects?)

Thanks for your inputs!
Best regards,
Robert