1. A method for keyword proximity searching a document database, comprising the steps of: (a) providing a query condition, the query condition having a plurality of keywords and a desired proximity distance between each of said plurality of keywords; (b) constructing a list for each keyword in the query condition, each list having a location of the keyword for each instance of the keyword in the document database; (c) performing a plane-sweep search of the lists to identify a first output tuple which satisfies the query condition; and (d) performing a nested-loop search of the lists to identify one or more output tuples within the desired proximity distance of said first output tuple.