US 7,552,128 B2
Compression of timestamps
Gaurav Bhalotia, 444 Castro St. Suite 109, Mountain View, Calif. 94041 (US); and Janardhanan Kadirkamanathan, 444 Castro St. Suite 109, Mountain View, Calif. 94041 (US)
Filed on Jan. 25, 2007, as Appl. No. 11/698,576.
Prior Publication US 2008/0183737 A1, Jul. 31, 2008
Int. Cl. G06F 7/00 (2006.01)
U.S. Cl. 707—100  [707/4] 14 Claims
OG exemplary drawing
 
8. A system for providing selected documents from a set of documents, in a time sensitive order to queries, comprising:
a memory for storing computer readable instructions, when executed by a processor, providing
a crawler that fetches said set of documents and document lists, and stores them in system files in a data directory;
a feed aggregator that inputs said system files, and at regular intervals produces a stream of document entries with details including its absolute timestamp;
an indexer that receives said stream of documents with absolute timestamps, and conducts the steps of,
storing a base timestamp at an index, wherein said base timestamp is the index build time; of the document computing the original timestamp differences of said documents, wherein said original timestamp difference is equal to the difference of the absolute timestamp from the base timestamp;
conducting a telescopic quantization of said original timestamp difference and storing a compressed value of said telescopically quantized time values at the index;
a query server that serves a query and presents a response to said query in the form of said selected documents from said set of documents, based on the recency of the documents found by the query, wherein said recency of the documents is determined by the calculation of the absolute timestamp, comprising the steps of,
retrieving said compressed value and decompressing the compressed value by the reverse of said telescopic quantization, wherein said step of retrieving is initiated in response to a search query;
obtaining the extracted timestamp difference by multiplying the compressed value by a time unit factor; and
subtracting said extracted timestamp difference from said base timestamp to derive the absolute timestamp.