Patent ID: 7356526

Claim:
A computer-based method for estimating a query compilation time of a query optimizer, said computer-based method implemented in computer readable program code stored in computer memory, said computer-based method comprising the steps of: (a) receiving a query; (b) iterating through possible join pairs for said query; (c) for each join pair, identifying a set of differentiating properties and using said identified set of differentiating properties to calculate number of join plans; (d) estimating the compilation time from said calculated number of join plans for each type of join method, said compilation time estimated via running regression of the following model: T=T inst Ã—Î£( C t Ã—P t ) wherein T is a machine-dependent parameter representing time per instruction, C t is a constant representing number of instructions to generate a join plan of type t, and P t is an estimated number of join plans of type t; and (e) outputting the estimated compilation time.