Oracle Built−in Packages- P57: Ah, for the good old days of Version of PL /SQL! Life was so simple then. No stored procedures or functions and certainly no packages. You had your set of built−in functions, like SUBSTR and TO_DATE. You had the IF statement and various kinds of loops. With these tools at hand, you built your batch−processing scripts for execution in SQL*Plus, and you coded your triggers in SQL*Forms , and you went home at night content with a good day's work done. | Appendix A What s on the Companion Disk PRIORITY PRIORITY ENQ_TIME ENQ_TIME this is the default ENQ_TIME PRIORITY Once a queue table is created with a specific ordering mechanism all queues in the queue table inherit the same default ordering. This order cannot be altered once the queue table has been created. If no sort list is specified all the queues in this queue table will be sorted by the enqueue time in ascending order. This order is equivalent to FIFO first-in-first-out order. Even with the default ordering defined a consumer can override this order by specifying the msgid or correlation value for a specific message. The msgid correlation and sequence_deviation take precedence over the default dequeueing order if they are specified. When you create a queue table the following objects are created The default exception queue associated with the queue table. It is named aq _ queue_table_name _e where queue_table_name is the name of the queue table just created. So if my queue table is named msg then my exception queue table is named aq _msg_e and now you can see why the maximum length name for a queue table is 24 characters . A read-only view that is used by AQ applications for querying queue data called aq queue_table_name . An index for the Queue Monitor operations called aq _ queue_table_name _t. An index or an index organized table IOT in the case of multiple consumer queues for dequeue operations. It is named aq _ queue_table_name _i Example In the following example I construct a basic queue table in the current schema with a comment as to when it was created BEGIN queue_table msg queue_payload_type message_type comment General message queue table created on TO_CHAR SYSDATE MON-DD-YYYY HH24 MI SS END Notice that I pass the payload type as a string the name of the object type I defined in the section explaining how to enqueue messages. I can verify the creation of this queue table by querying the USER_QUEUE_TABLES.
