192.1 Summary of DBMS_UNDO_ADV Subprograms

This topic lists the DBMS_UNDO_ADV subprograms in alphabetical order and briefly describes them.

Table 192-1 DBMS_UNDO_ADV Package Subprograms

Subprogram	Description
BEST_POSSIBLE_RETENTION Function	Returns the best possible value for the undo_retention parameter that the current undo tablespace can satisfy in order to maximize the usage of the current undo tablespace based on the historical information of the given period.
LONGEST QUERY Function	This function returns the duration of the longest query, in seconds, for a given period.
RBU_MIGRATION Function	Estimates the undo tablespace needed for migration from manual to automatic undo management.
REQUIRED_RETENTION Function	Returns the required value for the undo_retention parameter to satisfy the longest query based on undo statistics available for a given period.
REQUIRED_UNDO_SIZE Function	Returns the required undo tablespace size in MB to satisfy a certain undo retention value based on undo statistics available for a given period.
UNDO_ADVISOR Function	Uses the advisor framework to check if there is any problem with the current instance. It also provides recommendations.
UNDO_AUTOTUNE Function	Determines whether auto-tuning of undo retention is enabled for the current undo tablespace.
UNDO_HEALTH Function	Checks whether there is any problem with the current setting of undo retention and undo tablespace size based on the historical information of a given period and provides recommendations to fix the problem.
UNDO_INFO Function	Retrieves information about the undo tablespace of the current instance.