EP0224681A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method for managing obsolescence of data objects
Assignee: International Business Machines Corp
•
Filing: 1986-10-07
•
Granted: —
•
Expires: 2006-10-07
Abstract
Abstract Method for catculating the impact of a change to a source database operating in a system for managing obsolescence of replicas of data objects, the objects being utilized in multiple nodes (6,7,8) of a distributed processing system. At least one node in the distributed processing system operates as an object source location having access to source data objects (10) and at least one node (5) operates as an object replica location having means for storing replicas of requested objects received from a source location. The method for calculating the impact of a change to a source data object within the system described herein comprises the steps at source locations of: responsive to the change in the source data object, assigning a version number to the change and generating an identifier of a portion of the source database affected by the change; responsive to the generated identifier, generating a list of replicas formed from the affected portion of the source database; and for a replica location in communication with the source location recording a BADMESSAGES list of replicas in the list along with the version number assigned to the change for communication to the replica location.
Inventors
- 👤 Henry Martin Gladney
- 👤 Richard Lewis Mattson
- 👤 Douglas Jeffrey Lorch
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 06:26
CPC Classifications
G; G06; G06F; G06F16/00; G06F16/20; G06F16/27; G06F16/275; H; H04; H04L; H04L69/00; G06F2216/00; G06F2216/09; Y; Y10; Y10S; Y10S707/00; Y10S707/99951; Y10S707/99952; Y10S707/99954
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
180 words
In a system for managing obsolescence of replicas of data objects, the objects being utilized in multiple nodes (6,7,8) of a distributed processing system, at least one node operating as an object source location having access to a source database (10) and at least one node (5) operating as an object replica location having means for storing replicas of requested data objects received from a source location, a method for calculating the impact of a change to a source data object within the system, characterized by the steps at the source location of: responsive to the change in the source data object, assigning a version number to the change and generating an identifier of a portion of the source database affected by the change; responsive to the generated identifier, generating a list of replicas including objects from the affected portion of the source database; and for a replica location in communication with the source location, recording a bad messages list of replicas in the list along with the version number assigned to the change for communication to the replica location.
Claim 2
Dependent Claim
180 words
In a system for managing obsolescence of replicas of data objects, the objects being utilized in multiple nodes (6,7,8) of a distributed processing system, at least one node operating as an object source location having access to a source database (10) and at least one node (5) operating as an object replica location having means for storing replicas of requested data objects received from a source location, a method for calculating the impact of a change to a source data object within the system, characterized by the steps at the source location of: responsive to the change in the source data object, assigning a version number to the change and generating an identifier of a portion of the source database affected by the change; responsive to the generated identifier, generating a list of replicas including objects from the affected portion of the source database; and for a replica location in communication with the source location, recording a bad messages list of replicas in the list along with the version number assigned to the change for communication to the replica location.
Claim 3
Dependent Claim
73 words
The method of Claim 1, wherein said step of generating a list of replicas formed from the affected portion of the source database includes the steps of: maintaining for replicas supplied to replica locations a where used list of identifiers of portions of the source database used to form the respective replicas; and extracting the list of replicas including objects from the affected portion of the source database from the where used list.
Claim 4
Dependent Claim
17 words
The method of Claim 1, wherein the version number assigned is in the form of a timestamp.
Claim 5
Dependent Claim
44 words
The method of Claim 1, further including the steps of: maintaining a list of replica locations in communication with the source location; and wherein the step of recording a bad messages list is repeated for each replica location in the list of replica locations.
Claim 6
Dependent Claim
32 words
The method of Claim 1, wherein the generated identifier is a hash code based on requests identifying portions of the source database intended to be used in the generation of a replica.
Claim 7
Dependent Claim
24 words
The method of Claim 1, wherein the generated identifier includes at least a portion of the request used in the generation of the replica.
Claim 8
Dependent Claim
152 words
The method of claim 1, including the steps of: maintaining a list of replica locations in the system; responsive to the change in the source data object, assigning a version number to the change, generating a set of identifiers of portions of the source database affected by the change and entering the version number and set of identifiers in a change table; maintaining a where used table listing replicas supplied to replica locations and sets of identifiers of portions of the source database including objects used to form the replicas; joining the change table and where used table to generate a work table keyed by the version number associated with the change of replicas for those identifiers in the where used table that also occur in the change table; and generating a bad messages table associating the replica locations in the list of replica locations with the entries in the work table.
Claim 9
Dependent Claim
49 words
The method of Claim 7, further including the step of: responsive to several changes in the source database that are indicated to take effect as an atomic transaction, associating the same version number with each of the several changes, and with the respective entries in the bad messages table.
Claim 10
Dependent Claim
34 words
The method of Claim 7 or 8, further including the step of: deleting from the change table identifiers of portions of the source database successfully processed to create entries in the bad messages table.
Claim 11
Dependent Claim
31 words
The method of Claim 7, further including after the step of joining the change table and the where used table the step of: deleting any duplicate entries in the work table.
Claim 12
Dependent Claim
91 words
The method of Claim 7, further including after the step of joining the change table and the where used table the steps of: generating a new version of each replica in the work table that includes the change indicated by the version number associated with the replica; generating an old version of each replica in the work table that excludes the change indicated by the version number associated with the replica; and deleting replicas from the work table if the old version and the new version for such replicas are identical.
Claim 13
Dependent Claim
86 words
The method of Claim 10, further including prior to the step of deleting the steps of: for each version number in the bad messages table indicating a change to take effect in the future, generating a future version including the future change of each replica in the work list; and adding an entry to the bad messages list associating the version number indicating the change to take effect in the future with replicas in the work list if the future version differs from the new version.
Claim 14
Dependent Claim
84 words
The method of Claim 10, further including prior to the step of deleting the steps of: generating a newer version of each replica in the work table that includes all changes up to and including the changes associated with a version number indicating a future change, the version number indicating a future change being found in the bad messages table; adding the replica in question to the bad messages table together with the future change version number if the new and newer versions differ.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.