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:
Dec. 01, 2009
Filed:
Mar. 03, 2005
Wei Ming HU, Palo Alto, CA (US);
Mark Dilman, San Mateo, CA (US);
J. William Lee, Redwood Shores, CA (US);
Juan R. Loaiza, Redwood City, CA (US);
Vinay Srihari, South San Francisco, CA (US);
Wei Ming Hu, Palo Alto, CA (US);
Mark Dilman, San Mateo, CA (US);
J. William Lee, Redwood Shores, CA (US);
Juan R. Loaiza, Redwood City, CA (US);
Vinay Srihari, South San Francisco, CA (US);
Oracle International Corporation, Redwood Shores, CA (US);
Abstract
Techniques are provided for detecting lost writes so that data corruption can be avoided. According to one technique, lost writes are detected by comparing version numbers that are indicated in redo log entries with version numbers that are indicated in corresponding blocks in a standby database. According to one technique, which may be used in conjunction with the above technique, lost writes are detected by logging read operations that occur relative to a primary database, and comparing version numbers that are indicated in read log entries with version numbers that are indicated in corresponding blocks in a standby database. According to one technique, lost writes are detected by comparing, in response to read operations, (a) version numbers that are stored in a persistent in-memory cache with (b) version numbers that are indicated in corresponding blocks that are read from a primary database.