A queue table can contain multiple queues. In this case, each queue in a queue table has the same owner instance as the queue table. The DBA_QUEUE_TABLES columns are the same as those in ALL_QUEUE_TABLES.

USER_QUEUE_TABLES does not contain a column for OWNER.

Its columns are the same as those ALL_QUEUES. Oracle Database 12c Release 1 (12.1) introduces a new column SHARDED with data type VARCHAR2(5). The value for this column is TRUE for sharded queue, otherwise FALSE.

Oracle Database 12c Release 1 (12.1) introduces a new column SHARDED with data type VARCHAR2(5). The value for this column is TRUE for sharded queue, otherwise FALSE.

If the user has any Advanced Queuing system privileges, like MANAGE ANY QUEUE, ENQUEUE ANY QUEUE or DEQUEUE ANY QUEUE, this view describes all queues in the database. Oracle Database 12c Release 1 (12.1) introduces a new column SHARDED with data type VARCHAR2(5). The value for this column is TRUE for sharded queue, otherwise FALSE.

It also shows queues for which an enabled role on the queue is granted to PUBLIC.

This view is automatically created with each queue table and should be used for querying the queue data. The dequeue history data (time, user identification and transaction identification) is only valid for single-consumer queues.

In a queue table that is created with the compatible parameter set to '8.1' or higher, messages that were not dequeued by the consumer are shown as "UNDELIVERABLE". You can dequeue these messages by msgid. If the Oracle Database Advanced Queuing queue process monitor is running, then the messages are eventually moved to an exception queue. You can dequeue these messages from the exception queue with an ordinary dequeue.

A multiconsumer queue table created without the compatible parameter, or with the compatible parameter set to '8.0', does not display the state of a message on a consumer basis, but only displays the global state of the message.

When a message is dequeued using the REMOVE mode, DEQ_TIME, DEQ_USER_ID, and DEQ_TXN_ID are updated for the consumer that dequeued the message.

You can use MSGID and ORIGINAL_MSGID to chain propagated messages. When a message with message identifier m1 is propagated to a remote queue, m1 is stored in the ORIGINAL_MSGID column of the remote queue.

Beginning with Oracle Database 10g, AQ$Queue_Table_Name includes buffered messages. For buffered messages, the value of MSG_STATE is one of the following:

• IN MEMORY

  Buffered messages enqueued by a user

• DEFERRED

  Buffered messages enqueued by a capture process

• SPILLED

  User-enqueued buffered messages that have been spilled to disk

• DEFERRED SPILLED

  Capture-enqueued buffered messages that have been spilled to disk

• BUFFERED EXPIRED

  Expired buffered messages

For JMS Sharded Queues, the columns RETRY_COUNT, EXCEPTION_QUEUE_OWNER, EXCEPTION_QUEUE, PROPAGATED_MSGID, SENDER_NAME, SENDER_ADDRESS, SENDER_PROTOCOL, ORIGINAL_MSGID, ORIGINAL_QUEUE_NAME, ORIGINAL_QUEUE_OWNER, EXPIRATION_REASON are always NULL.

For JMS Sharded Queues, this view shows messages only for durable subscribers because non durable subscribers are session specific. The view returns data from the in-memory Sharded Queue message cache if available, otherwise from the values on disk. A user is required to be one of the following in order to query from AQ$<queue_name> view for Sharded Queues:

• user is the owner

• user has "dequeue" privilege on queue

• user has "dequeue any queue" privilege

The view has the following difference for Sharded Queues for 12c and future releases:

• MSG_PRIORITY is defined as NUMBER(38)

• MSG_STATE in a queue table does not have BUFFERED_EXPIRED hence the max length of UNDELIVERABLE is taken as length got MSG_STATE.

• EXPIRATION is defined as TIMESTAMP(6) WITH TIME ZONE in a queue table.

• USER_DATA column is defined using a decode on USERDATA_RAW and USERDATA_BLOB with UTL_RAW.CAST_TO_VARCHAR2.

• CONSUMER_NAME is defined as VARCHAR2(128)

It shows subscribers created by users with DBMS_AQADM.ADD_SUBSCRIBER and subscribers created for the apply process to apply user-created events. It also displays the transformation for the subscriber, if it was created with one. It is generated when the queue table is created.

This view provides functionality that is equivalent to the DBMS_AQADM.QUEUE_SUBSCRIBERS() procedure. For these queues, Oracle recommends that the view be used instead of this procedure to view queue subscribers. This view is created only for 8.1-compatible queue tables.

It also displays the transformation for the subscriber, if one was specified. It is generated when the queue table is created.

This view is created only for 8.1-compatible queue tables.

Its columns are the same as those in ALL_QUEUE_SUBSCRIBERS.

Its columns are the same as those in ALL_QUEUE_SUBSCRIBERS except that it does not contain the OWNER column.

These transformations can be specified with Advanced Queue operations like enqueue, dequeue and subscribe to automatically integrate transformations in messaging. This view is accessible only to users having DBA privileges.

To view the transformation definition, query USER_ATTRIBUTE_TRANSFORMATIONS.

Its columns are the same as those in DBA_SUBSCR_REGISTRATIONS.

In a Oracle Real Application Clusters environment, each instance keeps its own Oracle Database Advanced Queuing statistics information in its own System Global Area (SGA), and does not have knowledge of the statistics gathered by other instances. When a GV$AQ view is queried by an instance, all other instances funnel their Oracle Database Advanced Queuing statistics information to the instance issuing the query.

There is one row per queue per sender. The values are reset to zero when the database (or instance in an Oracle RAC environment) restarts.

There is one row per queue. The rows are deleted when the database (or instance in an Oracle RAC environment) restarts.

There is one row per queue table. The values are reset when the database (or instance in an Oracle RAC environment) restarts.

There is one row per instance per queue per subscriber. The rows are deleted when the database (or instance in an Oracle RAC environment) restarts.

There is one row per instance per queue per publisher. The rows are deleted when the database (or instance in an Oracle RAC environment) restarts.

The values are reset to zero when the database (or instance in a Oracle Real Application Clusters (Oracle RAC) environment) restarts, when propagation migrates to another instance, or when an unscheduled propagation is attempted.

The values are reset to zero when the database (or instance in a Oracle Real Application Clusters (Oracle RAC) environment) restarts, when propagation migrates to another instance, or when an unscheduled propagation is attempted.

This view lists performance statistics for the Oracle Database Advanced Queuing master background coordinator process (AQPC).

This view lists performance statistics per coordinator, for every AQ coordinator controlled by the AQ's Master coordinator.

Each job serves for forwarding messages for a shard from source instance to destination instance for a set of subscribers.

Latency denotes the predicted amount of time (in seconds) required from the current time to drain all the messages for that subscriber at each respective instance. The latency calculation considers past enqueue/dequeue rates and future enqueue/dequeue rates based on history.