Hi,
TREX is not compulsory...u need it only if ur data volume s very big...
I would like to know which field you are pulling from which table to fetch the BP count...what is your attribute ....is it house hold income? please post the reqirement in details for the forum members to get some answers for u.
try this out....take it step by step for now..break ur requirement into two parts and see if u can get the count alrite....then use the full requirement....
hope this helps!
Regards,
Aneesh