Re: When can the size of RMAN Level 0 shrink?

From: <yong321_at_yahoo.com>
Date: 28 May 2006 21:06:57 -0700
Message-ID: <1148875617.494993.35170@j33g2000cwa.googlegroups.com>

My own study note based on 9i RMAN says

RMAN Concepts manual states that "RMAN performs compression on its backups, which means that datafile blocks that have never been used are not backed up". This "never been used" is strictly enforced. If you have a big table and it's later truncated or most columns dropped, the space once used by that table still makes the backup piece big. RMAN doesn't care about segment high water mark; in fact, even after the table is dropped, space is still counted. The only way to reduce the size of the backup piece is shrink the datafile.

I need to check it again. In the meantime, critique is very welcome.

Yong Huang Received on Sun May 28 2006 - 23:06:57 CDT