Patent ID: 7574430

Claim:
A method of computing a first estimated synopsis error E 1 and a second estimated synopsis error E 2 for a plurality of N relations R={R 1 , R 2 . . . R N }, the first estimated synopsis error E 1 associated with a first set of synopses S 1 ={S 1 1 , S 2 1 , . . . S N 1 }, the second estimated synopsis error E 2 associated with a second set of synopses S 2 ={S 1 2 , S 2 2 , . . . S N 2 }, each synopsis S 1 i of the first synopsis set and each synopsis S 2 i of the second synopsis set associated with a respective ith relation R i , the method comprising: a) computing E 1 for a first allocation memory vector M 1 ={m 1 1 , m 2 1 , . . . m N 1 } where: ∑ i = 1 N ⁢ m i 1 = M 1 i ) ii) for an ith relation R 1 , each m i 1 represents a respective amount of memory allocated for a respective synopsis S 1 1 of the first synopsis set; b) using at least one of: i) said computed first estimated synopsis error E 1 ; and ii) stored intermediate results associated with said computing of E 1 , c) computing E 2 for a second memory allocation vector M 2 ={m 1 2 , m 2 2 , . . . m N 2 }, ∑ i = 1 N ⁢ m i 2 = M 2 i ) ii) for an ith relation R 1 , each m i 2 represents a respective amount of memory allocated for a respective synopsis S 2 1 of the second synopsis set; wherein M 1 ≠M 2 .