Patent ID: 8396860
Filing Date: 2013-03-12
Classification: G06F

Abstract:
1. A computer-implemented method comprising: receiving, by the computer, a query for optimization, the query including a SEQUENCED join between a temporal parent table and a temporal child table, the parent table having one or more rows; the child table having one or more rows; the parent table having a Primary Key (“PK”) column having a value for each row; the parent table having a temporal dimension, the parent table's temporal dimension having a value for each row; the child table having a Foreign Key (“FK”) column having a value for each row; the child table having a temporal dimension, the child table's temporal dimension having a value for each row; determining, by the computer, that the query, the parent table, the child table, and the join satisfy a set of CURRENT temporal join elimination criteria; determining, by the computer, that the query, the parent table, the child table, and the join satisfy a set of SEQUENCED temporal join elimination criteria, and in response: eliminating, by the computer, the join from the query to produce an optimized form of the query; wherein the join is a SEQUENCED inner join; the set of CURRENT temporal join elimination criteria comprises: the existence of temporal referential integrity (“RI”) between the temporal parent table and the temporal child table such that every FK value in the temporal child table exists as a PK value in the parent at the same time; the PK being declared as temporal-unique; the join not accessing any column other than PK columns from the temporal parent table; the join having a predicate of the form PK=FK; executing, by the computer, the optimized form of the query to produce a result, the result having one or more rows, the result having one or more projected columns, the projected columns having values, the result having a temporal dimension, the result's temporal dimension having a value; and storing the result in a memory by the computer.