A method for filtering a product transaction data file involves receiving, by a computer, a query including one or more groups of attribute conditions for filtering the product transaction data file. The attribute conditions in the query are applicable to product attribute data records split across a set of vertically split attribute data files. The method further includes determining which of the product attribute data records split across the set of vertically split attribute data files satisfy all of the one or more groups of attribute conditions in the query, identifying product keys associated with the product attribute data records that satisfy all of the one or more groups of attribute conditions in the query, and using the so-identified product keys to filter product data records in the transaction data file.