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

Comments embedded.
NetComrade wrote:
> My understanding is that RMAN lvl0 is _full_ backup of all datafiles
> whethere there is data in them or not.

Not quite true; a Level 0 backup copies all data blocks which have or did have data. If the blocks have never been used they aren't copied, so a new tablespace which at the time of the backup has not been used should not have any blocks copied from it.

> So is it safe to say that the
> only time an RMAN backup would shrink is when datafiles are dropped?

Or when the high-water mark of a table changes due to a truncate, or if a tablespace is recreated, reusing the same datafile, and re-loaded from an export as no 'empty but previously populated' blocks would exist. Or if the tablespace is recreated and untouched, as I stated above. Or, in 10g, when an 'ALTER TABLE ... SHRINK;' is executed. I'm not certain if an 'ALTER TABLE ... MOVE [TABLESPACE .....];' could also cause your backup to be reduced in size.

> This is a 9i db running on Windows
> .......
> We run Oracle 9iR2,10gR1/2 on RH4/RH3
> remove NSPAM to email

David Fitzjarrell Received on Fri May 26 2006 - 11:31:42 CDT