Messages with the same group process in first-in-first-out (FIFO) order. To group messages, complete the following steps. In the IN_EXTERN_MSG_GROUP table, insert the EXTERN_MSG_ID and an EXTERN_MSG_GROUP_ID. In the IN_EXTERN_MSG_SEQ table, insert the EXTERN_MSG_ID. Note: The EXTERN_MSG_ID is the same ID you used in the IN_EXTERN_MSG table. You can add more than one group to a message by inserting additional records into the IN_EXTERN_MSG_GROUP table. The EXTERN_MSG_ID and EXTERN_MSG_GROUP_ID columns have a limit of 64 characters. To create a new message, insert a record into the IN_EXTERN_MSG table with a unique value for the EXTERN_MSG_ID column.