Patent ID: 7840557

Claim:
A method for searching a document database, comprising: receiving a search query from a client system, said search query containing at least one term; in response to receiving the search query: transmitting a representation of said search query to a cache containing multiple query result entries, where a respective query result entry contains multiple query result segments, each of which comprises a list of documents produced in response to a prior execution of said search query; receiving, for said search query, multiple query result segments from said cache, wherein each query result segment of the multiple query result segments contains a list of documents produced in response to a prior execution of said search query on a distinct segment of the document database, the document database having multiple segments, each segment of the database containing a subset of the documents in the document database; for each respective query result segment received from said cache: determining whether said respective query result segment is a current version for said search query, and in response to determining that the respective query result segment received from said cache is not the current version, executing the search query to obtain the current version of the respective query result segment; and updating the respective query result segment stored in the cache using the obtained current version; and transmitting to the client system information corresponding to at least a portion of the documents listed in the current versions of the received query result segments.