The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 26, 2009
Filed:
Nov. 15, 2006
Philip A. Bernstein, Bellevue, WA (US);
Todd J. Green, Philadelphia, PA (US);
Sergey Melnik, Kirkland, WA (US);
Alan Nash, Los Gatos, CA (US);
Philip A. Bernstein, Bellevue, WA (US);
Todd J. Green, Philadelphia, PA (US);
Sergey Melnik, Kirkland, WA (US);
Alan Nash, Los Gatos, CA (US);
Microsoft Corporation, Redmond, WA (US);
Abstract
A general-purpose reusable algebraic-based composition algorithm for composing mappings between data schemas. The algorithm handles more expressive mappings, makes a best-effort to eliminate symbols when a perfect answer cannot be obtained, includes new heuristics, and is extensible. A relational algebraic language is provided wherein each mapping is expressed as a set of constraints, and each constraint is either a containment or equality of two or more relational algebraic expressions. The composition mechanism exploits monotonicity properties of algebraic operators in operator arguments, handles NULLs and bag semantics, operates to allow composition to produce a partial result when a complete result is not possible, facilitates symbols elimination one symbol at a time using left composition, for example, as a way of isolating the symbols, supports making a best-effort to eliminate as many symbols as possible from an intermediate schema, and handles unknown or partially known operators via delayed handling.