8.206 V$EQ_MESSAGE_CACHE_ADVICE

V$EQ_MESSAGE_CACHE_ADVICE shows simulated metrics for a range of potential message cache sizes for Transactional Event Queues (TEQs). This view assists in cache sizing by providing information in the form of metrics as described below.

Column	Datatype	Description
SIZE_FOR_ESTIMATE	NUMBER	Cache size for simulation (in megabytes)
SIZE_FACTOR	NUMBER	Size factor with respect to the current cache size
ESTD_SIZE_TYPE	VARCHAR2(9)	Possible values: MINIMUM: This cache size is required to have all dequeues in-memory (no uncached). CURRENT: This is the current size of the message cache. MAXIMUM: This cache size is required to have zero evictions. NULL: This is the value in all other cases.
ESTD_CACHED_PARTITIONS	NUMBER	Estimated number of cached event stream partitions for this size
ESTD_UNCACHED_PARTITIONS	NUMBER	Estimated number of uncached event stream partitions for this size
ESTD_EVICTIONS	NUMBER	Estimated number of event stream partitions evicted for this size
ESTD_EVICTION_RATE	NUMBER	Estimated number of event stream partitions getting evicted per minute
ESTD_FG_UNEVICTIONS	NUMBER	Estimated number of event stream partitions unevicted by foreground processes
ESTD_FG_UNEVICTION_RATE	NUMBER	Estimated number of event stream partitions getting unevicted by foreground processes
ESTD_BG_UNEVICTIONS	NUMBER	Estimated number of event stream partitions unevicted by background processes
ESTD_BG_UNEVICTION_RATE	NUMBER	Estimated number of event stream partitions getting unevicted by background processes
ESTD_BG_PROCESSES	NUMBER	Estimated number of background processes required for this size
TOTAL_ENQUEUE_RATE	NUMBER	Simulated number of messages being enqueued per second
TOTAL_DEQUEUE_RATE	NUMBER	Simulated number of messages being dequeued per second
AVG_PARTITION_SIZE	NUMBER	Simulated average number of messages per cached event stream partitions
AVG_PARTITION_MEMORY	NUMBER	Simulated average memory per cached event stream partition (in megabytes)
AVG_EVICTION_TIME	NUMBER	Simulated average time to evict a cached event stream partition (in milliseconds)
AVG_UNEVICTION_TIME	NUMBER	Simulated average time to unevict a cached event stream partition (in milliseconds)
FLAGS	NUMBER	Reserved for internal use
SIMULATION_TIME	NUMBER	Amount of time that was simulated for (in minutes)
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

Note:

This view is available starting with Oracle Database 21c.

See Also:

Oracle Database Advanced Queuing User's Guide for more information about Oracle Transactional Event Queues and Advanced Queuing