7.19 V$AQ_MESSAGE_CACHE_ADVICE

V$AQ_MESSAGE_CACHE_ADVICE shows simulated metrics for a range of potential message cache sizes. 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). PREFERRED: This is the smallest message cache size required to eliminate 80% of unevictions that occur with a message cache size of MINIMUM for subscribers who keep up, that is, subscribers whose dequeue rate matches the enqueue rate. MAXIMUM: This cache size is required to have zero evictions. NULL: This is the value in all other cases.
ESTD_CACHED_SUBSHARDS	NUMBER	Estimated number of cached subshards for this size
ESTD_UNCACHED_SUBSHARDS	NUMBER	Estimated number of uncached subshards for this size
ESTD_EVICTIONS	NUMBER	Estimated number of subshards evicted for this size
ESTD_EVICTION_RATE	NUMBER	Estimated number of subshards getting evicted per minute
ESTD_FG_UNEVICTIONS	NUMBER	Estimated number of subshards unevicted by foreground processes
ESTD_FG_UNEVICTION_RATE	NUMBER	Estimated number of subshards getting unevicted by foreground processes
ESTD_BG_UNEVICTIONS	NUMBER	Estimated number of subshards unevicted by background processes
ESTD_BG_UNEVICTION_RATE	NUMBER	Estimated number of subshards 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_SUBSHARD_SIZE	NUMBER	Simulated average number of messages per cached subshard
AVG_SUBSHARD_MEMORY	NUMBER	Simulated average memory per cached subshard (in megabytes)
AVG_EVICTION_TIME	NUMBER	Simulated average time to evict a cached subshard (in milliseconds)
AVG_UNEVICTION_TIME	NUMBER	Simulated average time to unevict a cached subshard (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