8.253 V$FS_LAG_HISTOGRAM

V$FS_LAG_HISTOGRAM displays histogram data about fast-start failover lag time.

Each minute, the primary database evaluates the lag time and increments the corresponding histogram bucket by one.

No rows are displayed when fast-start failover is disabled.

This view can be used to determine an appropriate value in your environment for the Data Guard broker property FastStartFailoverLagLimit.

Column	Datatype	Description
THREAD#	NUMBER	Redo thread number
LAG_TYPE	VARCHAR2(32)	Lag type (APPLY or TRANSPORT)
LAG_TIME	NUMBER	Indicates the upper bound (in seconds) for a specific lag time bucket Each bucket represents a range of lag times that are greater than the lower bucket's LAG_TIME (if any), but less than the LAG_TIME value shown in this column. All computed lag times that fall within this range are counted in this bucket.
LAG_COUNT	NUMBER	Number of times a computed lag value fell within this bucket
LAST_UPDATE_TIME	VARCHAR2(20)	Date and time at which this histogram row was last updated, indicating the most recent point at which the bucket count changed
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 AI Database 26ai.

See Also:

Oracle Data Guard Broker for more information on the FastStartFailoverLagLimit property