The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 05, 2002
Filed:
May. 11, 1999
Swarup Acharya, New Providence, NJ (US);
Viswanath Poosala, Highland Park, NJ (US);
Sridhar Ramaswamy, Scotch Plains, NJ (US);
Lucent Technologies INC, Murray Hill, NJ (US);
Abstract
The present invention provides various methods and apparatus for providing accurate estimates for point and range queries over two-dimensional rectangular data. However, the techniques of the present invention for rectangular data can be applied to data of other shapes, point data, or linear data. The present invention provides several grouping techniques for the approximating of spatial data. A method is disclosed for grouping a plurality of spatial inputs into a plurality of buckets. In one form of the present invention the plurality of spatial inputs, is grouped based on an equi-area partitioning technique. The equi-area partitioning technique can use the longest dimension of a bucket or bounding polygon as the criteria for splitting into further buckets or bounding polygons. An equi-count technique can also be used wherein the buckets are split using the highest projected spatial input count along a dimension as a splitting criteria. The bounding polygons may be minimum bounding rectangles. In one form of the present invention a method is provided which uses a grid of regions superimposed over a plurality of spatial inputs. The method can determine a measure of the density of the spatial inputs within each region of the grid of regions and uses this measurement of density to determine how to group the spatial inputs into buckets. When a query is received the present invention applies the query to the buckets created by whatever method and gives an estimate of the number of spatial inputs contained within the query by preferably assuming that spatial inputs are uniformly distributed within each bucket.