EP0420425A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A data processing system and method for updating a database therein
Assignee: International Business Machines Corp
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Filing: 1990-09-05
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Granted: —
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Expires: 2010-09-05
Abstract
Abstract A transaction processing system includes a primary active data base 52 and a tracking replica database 72. Change processing of the replica database is accomplished by separating redo records obtained from the transaction log 53 of the primary database into a plurality of respective queues 66. The redo records are separated such that all transaction records for a unit of transfer (page) of the primary database are placed on the same queue in log sequence. Each queue is linked exclusively to one of a plurality of parallel queue servers 68,69. Each queue server applies to the replica database the redo records in the queues which it exclusively serves. The replica database is thereby made consistent with the primary data by a lock-free updating mechanism which services the pages of the replica database in parallel.
Inventors
- 👤 Mohan Chandrasekaran
- 👤 Ronald L. Obermarck
- 👤 Richard K. Treiber
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 11:28
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/16; G06F11/20; G06F11/2097; G06F11/202; G06F11/2038; G06F11/2048; G06F16/00; G06F16/20; G06F16/27; G06F2201/00; G06F2201/80; Y; Y10; Y10S; Y10S707/00; Y10S707/99951; Y10S707/99952
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
104 words
A method for updating a tracking database (72), comprising the steps of: receiving log records from an active database (52) with which the tracking database is to be maintained consistent; maintaining a plurality of queues (66) of the log records, wherein all log records relating to any selected unit of physical storage are stored on the same queue; and simultaneously applying log records from two or more of said queues to the tracking database using a plurality of server processes (68, 69), wherein log records from any one queue are applied to the tracking database by only one server process at any given time.
Claim 2
Independent Claim
104 words
A method for updating a tracking database (72), comprising the steps of: receiving log records from an active database (52) with which the tracking database is to be maintained consistent; maintaining a plurality of queues (66) of the log records, wherein all log records relating to any selected unit of physical storage are stored on the same queue; and simultaneously applying log records from two or more of said queues to the tracking database using a plurality of server processes (68, 69), wherein log records from any one queue are applied to the tracking database by only one server process at any given time.
Claim 3
Dependent Claim
20 words
A method according to claim 1, wherein the log records are distributed between the queues using a hash process (65).
Claim 4
Dependent Claim
117 words
A data processing system including a tracking database (72) and means (60) for updating said database to maintain consistency with an active database (52), said means comprising: means (61) for receiving log records from the active database; a plurality of queues (66); distribution means (65) for placing said records on said queues such that all log records relating to any selected unit of physical storage are stored on the same queue; and a plurality of queue server means (68, 69) for simultaneously applying log records from two or more such queues to the tracking database, wherein log records from any one queue are applied to the tracking database by only one queue server at any given time.
Claim 5
Dependent Claim
117 words
A data processing system including a tracking database (72) and means (60) for updating said database to maintain consistency with an active database (52), said means comprising: means (61) for receiving log records from the active database; a plurality of queues (66); distribution means (65) for placing said records on said queues such that all log records relating to any selected unit of physical storage are stored on the same queue; and a plurality of queue server means (68, 69) for simultaneously applying log records from two or more such queues to the tracking database, wherein log records from any one queue are applied to the tracking database by only one queue server at any given time.
Claim 6
Dependent Claim
17 words
A data processing system according to claim 3, wherein said distribution means (65) is a hashing process.
Claim 7
Dependent Claim
52 words
A data processing system according to claim 3 or 4, further comprising the active database, in which data records are stored in units of transfer, and wherein all log records corresponding to a uni of transfer from said active database are stored on the same tracking database queue in their log sequence.
Claim 8
Dependent Claim
58 words
A data processing system according to Claim 5, in which each of said queue server means updates a unit of transfer from said tracking database by applying to the data records in a unit of transfer changes which are represented by the log records for a unit of transfer in the queue linked to said queue server means.
Claim 9
Dependent Claim
28 words
A data processing system according to claim 5 or claim 6, wherein said data processing system is adapted for transaction processing and said log is a transaction log.
Claim 10
Independent Claim
116 words
A method for maintaining consistency between an active database (52) and a tracking database (72) in a data processing system that includes a plurality of queue servers (68, 69), said method comprising the steps of: accumulating a sequence of log records (62) corresponding to changes made to said active database; maintaining a plurality of log record queues (66), wherein all log records for any selected unit of transfer of said first database are stored on the same queue; and simultaneously applying log records from two or more of said queues to said tracking database, wherein log records from any one queue are applied to said tracking database by only one queue server at any given time.
Claim 11
Independent Claim
116 words
A method for maintaining consistency between an active database (52) and a tracking database (72) in a data processing system that includes a plurality of queue servers (68, 69), said method comprising the steps of: accumulating a sequence of log records (62) corresponding to changes made to said active database; maintaining a plurality of log record queues (66), wherein all log records for any selected unit of transfer of said first database are stored on the same queue; and simultaneously applying log records from two or more of said queues to said tracking database, wherein log records from any one queue are applied to said tracking database by only one queue server at any given time.
References Cited (Backward Citations)
No citation records indexed.
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