Patent ID: 7720860

Claim:
A machine implemented method of querying an inverted index, the method comprising: storing a postings list of a term as a linked list of one or more nodes, each of the one or more nodes representing an item ID of an item containing the term; accumulating the postings list of the term into an update set comprising postings lists of other terms already accumulated; periodically flushing the update set to an inverted index to form a pulse in the inverted index, the pulse comprising a group of item IDs not occurring in any other pulse in the inverted index; receiving a query against the inverted index; processing the query starting with processing a starting node representing an item ID occurring in a current pulse of the inverted index, wherein the starting node is obtained from a sorted queue of nodes representing items containing a search term corresponding to the query; continuing processing the query continuing with processing a next node in the inverted index, the next node representing another item ID, the next node being next in the sorted queue of nodes representing items containing the search term corresponding to the query; determining that the next node in the sorted queue of nodes is beyond an end of the current pulse in which processing the query began; and returning a query result responsive to the query based on processing the nodes in the current pulse.