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USING "CONSISTENCY CHECK VALUE" AS OPTIMISTIC LOCKING VALUE FOR STAGING HOST PRODUCTION DATA AT CLIENT/SERVER FOR ACCESS BY...

IP.com Disclosure Number: IPCOM000013902D
Original Publication Date: 2001-Feb-01
Included in the Prior Art Database: 2003-Jun-19
Document File: 1 page(s) / 45K

Publishing Venue

IBM

Abstract

Using "CONSISTENCY CHECK VALUE" as optimistic locking value for staging Host production data at Client/Server for access by IMS CSOBJECT Client/Server feature.

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  USING "CONSISTENCY CHECK VALUE" AS OPTIMISTIC LOCKING VALUE FOR STAGING HOST PRODUCTION DATA AT CLIENT/SERVER FOR ACCESS BY...

    Using "CONSISTENCY CHECK VALUE" as optimistic locking value for staging Host production data at Client/Server for access by IMS CSOBJECT Client/Server feature.

By generating a Consistency Check Value (CCV) from the data within the IMS/ESA and/or DB2 data base, an optimistic lock value can be generated and stored in the CSobject Lock Table to provide a checking value that can be validated for a change request (ADD, DELETE, and UPDATE) to insure that the IMS and/or DB2 data has been transmitted to the Client /Server or has not been changed at the Host by a Host application. Since the data being sent to the Client/Server is used to create the CCV, the same data fields can be used to determine if the Host data has changed since it was staged at the Client/Server. The CCV value can be actual data fields, a time stamp that exists within the Host data, or a technique such as 32-bit (long) arithmetic to accumulate a sum, and then fold the resulting 16-bit value by adding any carry bits into the sum explicitly, and returning ones compliment of the result. When a Client/Server application makes a request to the Host, CSobject will pass the result to a user method at the Host. For a RETRIEVAL request, for an UPDATE lock, the user Host method will construct the CCV and pass it to CSobject on a send request. CSobject will store the CCV in the CSobject lock table. For a DELETE request, CSobject will pass the CCV to the Host application that was created on the RETRIEVAL request for CCV validation. The user Host applicatio...