RE: Shrink Table: IEstimating Rollback Space

From: Bort, Guillermo <>
Date: Fri, 17 Oct 2008 10:02:38 -0500
Message-ID: <>

If you use cascade the indexes will shrink, however I'm not certain this would be the ideal choice. In order to increase performance I'd drop the indexes, re-organize the table (dbms_redefinition or alter table move) and re-build the indexes.


Guillermo Alan Bort
DBA / DBA Main Team

EDS, an HP company
-----Original Message-----
[] On Behalf Of Hemant K Chitale Sent: Friday, October 17, 2008 11:47 AM
To:; Subject: Re: Shrink Table: IEstimating Rollback Space

Undo (and Redo !) will be quite noticeable-- more so as you have indexes on the table.

A SHRINK operates as a DELETE (which will be the very significant portion of Undo) *and* an INSERT.
Both operations also have to update Indexes . The Indexes will not shrink until and unless you do a COALESCE or REBUILD. See MetaLink Note#577375.1 and Bug# 3888229.

Hemant K Chitale

Received on Fri Oct 17 2008 - 10:02:38 CDT

Original text of this message