DROP ROLLBACK SEGMENT

Purpose

Use the DROP ROLLBACK SEGMENT to remove a rollback segment from the database. When you drop a rollback segment, all space allocated to the rollback segment returns to the tablespace.

Note:

If your database is running in automatic undo mode, then this is the only valid operation on rollback segments. In that mode, you cannot create or alter a rollback segment.

Prerequisites

You must have the DROP ROLLBACK SEGMENT system privilege, and the rollback segment must be offline.

Syntax

drop_rollback_segment::=

Description of the illustration drop_rollback_segment.eps

Semantics

rollback_segment

Specify the name the rollback segment to be dropped.

Restrictions on Dropping Rollback Segments

This statement is subject to the following restrictions:

You can drop a rollback segment only if it is offline. To determine whether a rollback segment is offline, query the data dictionary view DBA_ROLLBACK_SEGS. Offline rollback segments have the value AVAILABLE in the STATUS column. You can take a rollback segment offline with the OFFLINE clause of the ALTER ROLLBACK SEGMENT statement.
You cannot drop the SYSTEM rollback segment.

Examples

Dropping a Rollback Segment: Example

The following syntax drops the rollback segment created in "Creating a Rollback Segment: Example":

DROP ROLLBACK SEGMENT rbs_one;