Patent Number: 6,311,181

Title: Multi-dimensional selectivity estimation method using compressed histograminformation

Abstract: Disclosed is a multi-dimensional selectivity estimation method usingcompressed histogram information which the database query optimizer in adatabase management system uses to find the most efficient execution planamong all possible plans. The method includes the several steps togenerate a large number of small-sized multi-dimensional histogrambuckets, sampling DCT coefficients which have high values with highprobability, compressing information from the multi-dimensional histogrambuckets using a multi-dimensional discrete cosine transform(DCT) andstoring compressed information, and estimating the query selectivity byusing compressed and stored histogram information as the statistics.

Inventors: Lee; Ju-Hong (Seoul, KR), Kim; Deok-Hwan (Seoul, KR), Chung; Chin-Wan (Seoul, KR)


International Classification:

Expiration Date: 10/32013