1. Database Reference
  2. Dynamic Performance Views
  3. Dynamic Performance (V$) Views: V$SCHEDULER_RUNNING_JOBS to V$ZONEMAP_USAGE_STATS
  4. V$TEMPUNDOSTAT

9.114 V$TEMPUNDOSTAT

V$TEMPUNDOSTAT shows various statistics related to the temporary undo log for this database instance. It displays a histogram of statistical data to show how the system is working. Each row in the view keeps statistics collected in the instance for a 10-minute interval. The rows are in the descending order of the BEGIN_TIME column value. This view contains a total of 576 rows, spanning a 4-day cycle. This view is similar to the V$UNDOSTAT view.
Column Datatype Description

BEGIN_TIME

DATE

Identifies the beginning of the time interval

END_TIME

DATE

Identifies the end of the time interval

UNDOTSN

NUMBER

Represents the last active undo tablespace in the duration of time. The tablespace ID of the active undo tablespace is returned in this column. If more than one undo tablespace was active in that period, the active undo tablespace that was active at the end of the period is reported.

TXNCOUNT

NUMBER

Total number of transaction that have bound to the temp undo segment contained in above tablespace within the interval period

MAXCONCURRENCY

NUMBER

Highest number of transactions executed concurrently which modified temporary objects within the interval period

MAXQUERYLEN

NUMBER

Reserved for future use

MAXQUERYID

VARCHAR2(13)

Reserved for future use

UNDOBLKCNT

NUMBER

Total number of temporary undo blocks consumed

EXTCNT

NUMBER

Total number of extents consumed

USCOUNT

NUMBER

Temp undo segments created in this period

SSOLDERRCNT

NUMBER

Identifies the number of times the error ORA-01555 occurred. You can use this statistic to decide whether or not the UNDO_RETENTION initialization parameter is set properly given the size of the undo tablespace. Increasing the value of UNDO_RETENTION can reduce the occurrence of this error.

NOSPACEERRCNT

NUMBER

Total number of times the error 'no space left for temporary undo' was raised

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:

"V$UNDOSTAT"