7.202 V$EVENT_HISTOGRAM

V$EVENT_HISTOGRAM displays a histogram of the number of waits, the maximum wait, and total wait time on an event basis, in milliseconds. The histogram has buckets of time intervals from < 1 ms, < 2 ms, < 4 ms, < 8 ms, ... < 2²¹ ms, < 2²² ms, and >= 2²² ms.

The histogram will not be filled unless the TIMED_STATISTICS initialization parameter is set to true.

Column	Datatype	Description
EVENT#	NUMBER	Event number
EVENT	VARCHAR2(64)	Name of the event
WAIT_TIME_MILLI	NUMBER	Amount of time the bucket represents (in milliseconds). If the duration = num, then this column represents waits of duration < num that are not included in any smaller bucket.
WAIT_COUNT	NUMBER	Number of waits of the duration belonging to the bucket of the histogram
LAST_UPDATE_TIME	VARCHAR2(64)	Indicates the last time the bucket was updated (the ending timestamp of the last wait falling into the bucket's duration)
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:

"TIMED_STATISTICS"