FW: [Fwd: Re: Large exports on NT]

OK. I can accept that. We are pretty primitive here as far as Oracle goes. = Only 1 tape drive and few disks to use. Pretty sad. I don't use RMAN = though I plan to start playing with it soon. So far (knock on wood) I've = never lost a datafile so I hadn't thought of that situation. All my = recovery to date has been the entire database.

Our "old" setup (before I got forced into Oracle) had autoextend with no = maxsize. The "new" setup I did limits it to 4GB datafiles so as least I'm = making progress I guess. 8o)

Michael Ray
Oracle DBA
TRW, Marshall, IL
217-826-3011 x2438

>>> drake_at_psscorp.com 11/10/00 02:07PM >>> Micheal,

> Why would it be any faster to get 8 x 2GB datafiles from tape=20
> for a tablespace than 1 x 16GB one?

Only for the case of where you lose one datafile (say from a writefile() error from a RAID controller) so you then only need to bring one datafile back from tape,=20 and recover the one datafile, not the entire database.

RMAN does allow for parallelization, so there can be benefits for having multiple datafiles for backup and restore, if you are backing up to disk = or
multiple tape drives.

Single tape drive, no difference betwee 8 x 2 GB or 16 x 1 GB - limited by write/read rate of tape device.

If you have enough disks, there's some improvement in performance by = having
multiple datafiles for that tablespace on different disks (different controllers ... I'm dreaming) - obvious stuff, nothing new. I wonder if there is any latch contention improvements if you have multiple datafiles.

Heading off topic, but one other thing - if you have multiple datafiles in your Rollback Segments (for example) tablespace and one datafile goes offline, you still have other rollback segments available to handle transactions.

liking lots of smaller datafiles ... Received on Fri Nov 10 2000 - 14:31:15 CST