186.1.4 REQUIRED_RETENTION Function
This function returns the required value for the undo_retention
parameter to satisfy the longest query based on undo statistics available for a given period.
Syntax
Viewing the output using the historical information in memory:
DBMS_UNDO_ADV.REQUIRED_RETENTION()
RETURN NUMBER;
Viewing the output using start time and end time:
DBMS_UNDO_ADV.REQUIRED_RETENTION(
start_time IN DATE,
end_time IN DATE)
RETURN NUMBER;
Viewing the output using begin and end AWR snapshot ID:
DBMS_UNDO_ADV.REQUIRED_RETENTION(
begin_snap IN NUMBER,
end_snap IN NUMBER)
RETURN NUMBER;
Parameters
Table 186-5 REQUIRED_RETENTION Function Parameters
Parameter | Description |
---|---|
|
Start time of the given period. |
end_time |
End time of the given period. |
begin_snap |
Begin snapshot identifier. It is based on historical information in AWR from the |
end_snap |
End snapshot identifier. It is based on historical information in AWR until the |