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:
Jan. 26, 1999
Filed:
Dec. 16, 1996
Philip Lewis Bohannon, Mt. Tabor, NJ (US);
Rajeev Rastogi, New Providence, NJ (US);
Abraham Silberschatz, Summit, NJ (US);
Sundararajarao Sudarshan, Powai, IN;
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
For use with an active database stored in volatile memory for direct revision thereof, the active database having multiple checkpoints and a stable log, having a tail stored in the volatile memory, for tracking revisions to the active database to allow corresponding revisions to be made to the multiple checkpoints, the active database subject to corruption, a system for, and method of, restoring the active database and a computer system containing the same. The system includes: (1) a checkpoint determination controller that determines which of the multiple checkpoints is a most recently completed checkpoint and copies the most recently completed checkpoint to the volatile memory to serve as an unrevised database for reconstructing the active database and (2) a revision application controller that retrieves selected ones of the revisions from the stable log and the tail and applies the revisions to the unrevised database thereby to restore the active database. In an advantageous embodiment, the applied revisions include log records at an operation level (lower level of abstration than transactions), and the revision application controller, using memory locks while restoring the active database, releases ones of the memory locks as a function of applying ones of the log records.