What is default undo retention period in Oracle 10g?

What is default undo retention period in Oracle 10g?

300 seconds
The default is 300 seconds (5 minutes), and you can set this parameter to guarantee that Oracle keeps undo logs for extended periods of time. Rather than having to define and manage rollback segments, you can simply define an Undo tablespace and let Oracle take care of the rest.

What is undo retention in Oracle?

When automatic undo management is enabled, there is always a current undo retention period, which is the minimum amount of time that the Oracle Database attempts to retain old undo information before overwriting it.

How do I change undo retention in Oracle?

Setting the Minimum Undo Retention Period

1. Set UNDO_RETENTION in the initialization parameter file. UNDO_RETENTION = 1800.
2. Change UNDO_RETENTION at any time using the ALTER SYSTEM statement: ALTER SYSTEM SET UNDO_RETENTION = 2400;

What is the value of undo retention in Oracle?

UNDO_RETENTION. Oracle recommends that multiple instances have the same value. UNDO_RETENTION specifies (in seconds) the low threshold value of undo retention. For AUTOEXTEND undo tablespaces, the system retains undo for at least the time specified in this parameter, and automatically tunes the undo retention period to satisfy

What happens to the undo space in Oracle?

Oracle automatically manages the undo space and will dynamically decrease the retention below the undo retention setting if space constraints require it. The caveat to that is when the undo tablespace has guaranteed retention.

How to set a minimum undo retention period?

You can optionally specify a minimum undo retention period (in seconds) by setting the UNDO_RETENTION initialization parameter. The exact impact this parameter on undo retention is as follows: The UNDO_RETENTION parameter is ignored for a fixed size undo tablespace.

How does the retention period work in Oracle?

Automatic tuning of Undo Retention. Oracle database automatically tunes the undo retention period based on how the undo tablespace is configured. 1. If the undo tablespace is fixed size, the database tunes the retention period for the best possible undo retention for that tablespace size and the current system load.