In general the default version numbers are set to 1 so that a simple recompile of the app, or a part of the app, should not cause the application behaviour to change or cause the queue manager to refer to fields in the structure which may not be initialized, or even allocated in memory.
For example, on the distributed platforms, a message put with a V1 MQMD is not subject to the queue manager checking the validity of the MQ headers in the payload, while a message put with a V2 MQMD is subject to the queue manager checking the validity of the MQ headers in the payload. At V5.0 (when the MQMD V2) was introduced we decided that it was better to discover an invalid header at the point the bad message entered the MQ network, rather than when the data was used, and added this checking. To ensure compatibility we only enabled the checking if the version number was 2, thus ensuring compatibility with all existing apps even if they were recompiled. Andy. "Kasischke, Bob" <[EMAIL PROTECTED]>@AKH-WIEN.AC.AT> on 05/09/2002 10:27:06 PM Please respond to MQSeries List <[EMAIL PROTECTED]> Sent by: MQSeries List <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] cc: Subject: Re: Version Number I think the answer is ... because. IBM just decided to set it to 1.� I know the C API does the same thing. Now the Java Client (MA88) on the other hand sets all versions to 2.� Why 2?� I couldn't find anything in the pubs that describes why they use 2 and of course it leads to great confusion when things work with C clients and not with Java Clients. -----Original Message----- From: Robert Broderick [mailto:[EMAIL PROTECTED]] Sent: Wednesday, May 08, 2002 1:29 PM To: [EMAIL PROTECTED] Subject: Version Number OK Two dollar question here. OS390 MQ v 5.2 The CMQV has upwards of version 3 available for the MQOD. Why does the CMQODV copybook have a default vaule of version one (1) specified. Is this because of downward compatability (or something) or has the wrong copybook been installed or must you force (which is what we did) the version number to open up the additional functionality????? ��������������������������������������� bobbee _________________________________________________________________ Chat with friends online, try MSN Messenger: http://messenger.msn.com Instructions for managing your mailing list subscription are provided in the Listserv General Users Guide available at http://www.lsoft.com Archive: http://vm.akh-wien.ac.at/MQSeries.archive *********************************************************************************** WARNING: All e-mail sent to and from this address will be received or otherwise recorded by the A.G. Edwards corporate e-mail system and is subject to archival, monitoring or review by, and/or disclosure to, someone other than the recipient. ************************************************************************************ Instructions for managing your mailing list subscription are provided in the Listserv General Users Guide available at http://www.lsoft.com Archive: http://vm.akh-wien.ac.at/MQSeries.archive
