Boots – shoes – and leggings
Patent
1994-10-27
1996-03-12
Black, Thomas G.
Boots, shoes, and leggings
364DIG1, 3642821, 3642824, G06F 1730
Patent
active
054993679
ABSTRACT:
The present invention provides a distributed log system where the logs are distributed on a per client basis. That is, the clients are partitioned into subsets. Each subset of clients is assigned a log, and the the redo records of those clients are maintained in that log. This reduces contention bottlenecks, because the number of clients writing to any one log is limited. Also, all of a client's changes are stored in a single log. During a recovery process, the changes for a block of data may be stored in different logs. For proper recovery, the changes must be applied to the database in the order in which they were originally made. The present invention provides a system for ordering the log entries in the correct order by using a "sequence number". Each page of data in the database has an associated sequence number. When a change is made to that page, the sequence number is incremented. The new sequence number is written to the log along with the change information. To minimize overhead, the sequence number is structured as a two part value. The first part of the value is an "incarnation number" that is increased whenever the associated change assigns a new value to the entire data block that is independent of its prior value, such as the change that initiates a block.
REFERENCES:
patent: 4648031 (1987-03-01), Jenner
patent: 4819159 (1989-04-01), shipley et al.
patent: 4878167 (1989-10-01), Kapulka et al.
patent: 4897781 (1990-01-01), Chang et al.
patent: 5008853 (1991-04-01), Bly et al.
patent: 5095421 (1992-03-01), Freund
patent: 5140689 (1992-08-01), Kobayashi
patent: 5165031 (1992-11-01), Pruul et al.
patent: 5201044 (1993-04-01), Frey, Jr. et al.
patent: 5222217 (1993-06-01), Blount et al.
patent: 5225977 (1993-07-01), Hooper et al.
patent: 5261089 (1993-11-01), Coleman et al.
patent: 5276876 (1994-01-01), Coleman et al.
patent: 5327556 (1994-07-01), Mohan et al.
patent: 5363505 (1994-11-01), Maslak et al.
Kumar, "A Crash Recovery Algorithm Based on Multiple Logs that Exploits Parallelism", Proc. Second IEEE Symposium on Parallel and Distributed Computing, 9-13 Dec. 1990, pp. 156-159.
Levy, "Incremental Restart", Proc. Seventh International Conference on Data Engineering, 8-12 Apr. 1991, pp. 640-648.
Bamford Roger J.
Howard Forrest W.
Kabcenell Dirk A.
Miner Robert N.
Amsbury Wayne
Black Thomas G.
Oracle Corporation
LandOfFree
System for database integrity with multiple logs assigned to cli does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System for database integrity with multiple logs assigned to cli, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System for database integrity with multiple logs assigned to cli will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2107460