Abstract: A method and apparatus are presented for: receiving a search query, comprising a query select statement and a plurality of search terms; generating a plurality of selection models based on the query select statement and the plurality of search terms, wherein each selection model, from the plurality of selection models, comprises a unique combination of one or more terms, from the plurality of search terms, that is not present in other selection models, from the plurality of selection models. A plurality of particular selection results is obtained for a particular selection model for each particular selection model, from the plurality of models. The plurality of particular selection results are grouped to a final result and aggregated according to the selection models, and the aggregated final result is presented to a user.

Abstract: A search engine comprising a crawler which crawls the WWW and stores pages found on the WWW in a database. An indexer indexes the pages in the database to produce a primary index. A document mapping section maps pages in the database into a plurality of tiers based on a ranking of the pages. The ranking may be based on portions of the pages which have a relatively higher value context. A processor produces a plurality of sub-indices from the primary index based on the mapping. The sub-indices are stored in a search node cluster. The cluster is a matrix of search nodes logically arranged in a plurality of rows and columns. Search nodes in the same column include the same sub-index. Search nodes in the same row include distinct sub-indices. A search query received by a user is sent to a dispatcher which, in turn, forwards the query to the first tier of search nodes. A fall through algorithm is disclosed which indicates when the dispatcher should forward the search query to other tiers of search nodes.