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Sybrand Bakker wrote:
> On 14 Jul 2006 04:16:04 -0700, "Charles Hooper"
> <hooperc2000_at_yahoo.com> wrote:
>
> >* Pre-create the tablespaces to reduce the time that it takes to
> >perform the import, and to reduce fragmentation at the operating system
> >level - if you know that you will need a 25GB data file for a
> >tablespace, create the data file at that size before the import.
>
> As a datafile in many cases is the smallest unit of recovery, anything
> beyond 2 Gb is IMO undesirable, and 25 Gb is just asking for trouble.
>
> --
> Sybrand Bakker, Senior Oracle DBA
That is a point that I had not considered. I was looking at it in terms of performance after the creation - less hard drive track to track seeking.
To help my understanding, what if the tablespace were 25GB in size, and you therefore have at least 13 - 2GB data files for the tablespace. You find that the twelfth data file for the tablespace is corrupt. Can you recover just that data file? My suspicion is that the tables and indexes, which have data blocks in that data file likely are not completely contained within that data file, but rather have data blocks in several of the data files. If you were to recover just this corrupted data file, would that not leave the database in an inconsistent state?
What about bigfile tablespaces, which support single data files up to 128TB? Is there no point in considering bigfile tablespaces?
Charles Hooper
PC Support Specialist
K&M Machine-Fabricating, Inc.
Received on Fri Jul 14 2006 - 15:52:44 CDT