Retrieval of group messages

The IBM® MQ adapter selects group messages for retrieval based upon three possible selection criteria:

When the Group Message adapter command (-GRP) is specified, the GroupId is used as the sole selection criteria for group message retrieval. If the Message ID adapter command (-MID) or the Correlation ID adapter command (-CID) is specified, the respective selection criteria are also used.

Be sure to organize message segments and groups on output when you specify the GroupId, MsgSequenceNumber, Offset, and MsgFlags fields in the MessageDescriptor type. Improper use of these fields could result in incomplete message groups and illogical messages on the output queue.