Aggregates ?? Datamart (to whatever it has implemented a DataMart using Postgres)

This is the Problem:

I'm building a Large DataMart with a big table and I want to improve the performace using aggregates I mean a set of table that store some specific aggregacion of the main table, like materialized views, I know that this feature is not implemented yet in postgres, And I see a interesting article to implementing this using a set of triggers, but I thing the big problem is not the rate of the updates or the real time consistence between both table, the main and the agregates. I thing the really problem is how to let it know to the RDMS engine that this aggregates exist!, I mean when I run a query I want to the Database engine run the query against the correct table.

I thing if some day postgres allow to do this, will could use postgres more confortablement in Data warehouse proyect.

I read today the TODO list of postgres and I don't see anithing like this...
Any alternative??

or how you solve the problem of the agregates in yours DataMarts???

any commentari is well recived