Patent ID: 6618719
Filing Date: 2003-09-09
Classification: G06F,Y10S

Abstract:
In a computer system having a processor, a memory, and a storage device, said storage device storing a database comprising rows of data records, each data record storing information in database columns, said database including an optimizer for selecting a query execution plan specifying how a given database query is executed, a method for executing a database query for selecting particular ones of said data records, the method comprising:(a) receiving from a user specification of a database query specifying selection of particular ones of said data records, said database query comprising an expression specifying a query condition; (b) providing a language interface to the optimizer, through which it can be given a user-provided description of a particular desired query execution plan for said specified database query; (c) through said language interface, receiving from the user specification of the desired query execution plan for said specified database query, the language interface defining a declarative language syntax that allows description of the desired query execution plan in abstract terms, said specification of the desired query execution plan comprising a relational algebra describing the desired execution plan for said specified database query without specifying a particular sequence of operations that the database system must follow; (d) storing said specified desired query execution plan as a reusable object; and (e) when executing said database query, performing substeps of: (i) retrieving said specified desired query execution plan; and (ii) executing said database query according to the query execution plan set forth in said retrieved specified desired query execution plan.