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:
Jun. 15, 2010
Filed:
Mar. 19, 2004
Per-åke Larson, Redmond, WA (US);
Jonathan David Goldstein, Kirkland, WA (US);
Raghu Ramakrishnan, Madison, WI (US);
Hongfei Guo, Madison, WI (US);
Per-Åke Larson, Redmond, WA (US);
Jonathan David Goldstein, Kirkland, WA (US);
Raghu Ramakrishnan, Madison, WI (US);
Hongfei Guo, Madison, WI (US);
Microsoft Corporation, Redmond, WA (US);
Abstract
Currency and consistency requirements are specified as part of a query against a database that may contain replicated data that is updated asynchronously and therefore may not be completely up to date. The database system constructs query execution plans that include an input selection operator that verifies the currency of a replica and selects a subplan using the replica for execution only when the replica meets the query's currency constraints. It checks possible query execution plans at construction time against the query's consistency constraints and any plans that may produce a result not meeting the consistency constraints are rejected. In this way, the query result is guaranteed to satisfy the query's currency and consistency requirements.