Patent ID: 6957210

Claim:
A method for performing an exclusion join of at least a first table T 1 and a second table T 2 , where each of the tables has an associated Star Map, S 1 and S 2 , respectively, and each Star Map includes bitmap entries having locations indexed by a hash of one or more values associated with one or more join key columns of its associated table, where a bitmap entry in a Star Map, if set, indicates the presence of one or more rows in its associated table that has entries in the one or more join key columns that together hash to the location of the bitmap entry, the method including: a) performing one or more Boolean operations using the bitmap entries of the Star Maps S 1 and S 2 to produce bitmap entries in a Star Map SJ where there is a corresponding set bitmap entry in S 1 and no corresponding set bitmap entry in S 2 ; b) using SJ to identify qualifying rows from the first table T 1 ; and c) providing the qualifying rows as an exclusion join result.