7.18 V$AQ_MESSAGE_CACHE

V$AQ_MESSAGE_CACHE provides performance statistics of the message cache for sharded queues at the subshard level in the instance.

Column Datatype Description

QUEUE_ID

NUMBER

Queue ID

SHARD_ID

NUMBER

Shard ID

PRIORITY

NUMBER

Priority of the subshard for dequeue, range 0-9

SUBSHARD_ID

NUMBER

Subshard ID in the shard

PARTITION_ID

NUMBER

Partition id for the particular subshard

MAX_MSGS

NUMBER

Maximum number of messages of subshard

ENQUEUED_MSGS

NUMBER

Number of messages enqueued for the subshard

MSGS_MADE_EXPIRED

NUMBER

Number of messages made expired

CHUNK_SIZE

NUMBER

The size of the memory chunk for storing messages

NUM_CHUNKS

NUMBER

Number of chunks for the subshard

NUM_FREE_CHUNKS

NUMBER

Number of free chunks for the subshard

USED_MEMORY_SIZE

NUMBER

Total estimated size of memory in use (in bytes) for the subshard

STATE

VARCHAR2(13)

Subshard state. Possible values:

  • CACHED (in memory)

  • UNCACHED (on disk)

  • UNCACHED_FREE

  • CACHED_FREE

  • UNKNOWN

CON_ID

NUMBER

The ID of the container to which the data pertains. Possible values include:

  • 0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.

  • 1: This value is used for rows containing data that pertain to only the root

  • n: Where n is the applicable container ID for the rows containing data

See Also:

Oracle Database Advanced Queuing User's Guide for more information about Oracle Database Advanced Queueing