6. The apparatus of claim 3 , wherein determining which of the one or more record combinations to evaluate comprises maintaining a current record combination including a last non-discarded, non-ignored record read from the hierarchical data storage.
6. The apparatus of claim 3 , wherein determining which of the one or more record combinations to evaluate comprises maintaining a current record combination including a last non-discarded, non-ignored record read from the hierarchical data storage. 9. The apparatus of claim 6 , wherein the one or more processors are further configured to: deconstruct the predicates of the received query into one or more conjuncts, each of the one or more conjuncts including a single operation; evaluate each of the conjuncts for the current record combination when a record is added to the record combination; when the conjunct is not satisfied, identify the current record combination with the added record as a mismatch; and ignore any record in the received hierarchically clustered data stream that is a child of the added record that resulted in the mismatch.