Re: Slow Oracle Export???

From: Tim Irvin <irvin_at_lmsc.lockheed.com>
Date: 1996/09/09
Message-ID: <irvin-0909960813420001_at_butch.lmsc.lockheed.com>#1/1


In article <32311d4b.175274136_at_news.concentric.net>, jljoslin_at_cris.com (J L Joslin) wrote:

> On 2 Sep 1996 16:56:15 GMT, Vijay Vardhineni 604-1835 <vvardh01>
> wrote:
 

> >I'm running Oracle 7.2 on an HP9000. An export on a 1.5 GB table is
 taking about 7 hours. I've tried a bunch of different values f=
> >or exp, but it doesn't seem to make a difference. We are using a fast
 cybernetics CY-8505 tape drive. Anyone have any suggestions?=
> >
>
> AH HA! You're running the export to TAPE! Possibly the slowest mass
> storage device known to man. Export the data to disk first. It'll be a
> whole lot faster and your export dump file will not be even close to
> the full 1.5GB in the table.

Indeed. We do cold backups on two databases nightly, starting at 12:30 AM. The previous DBA just shut the databases down, sequentially, copying all database files and corresponding file system data (files maintained by version control system which must be in sync with oracle) to tape and then restarted the databases. This took us until 5:30 or 6:00 AM for less than 500 MB of total backup. (He was also using a *remote* tape device, slowing it down even more).

I changed it last week to backup to disk, tarring up everything associated with each database. After the disk backup was complete, I restarted the database and then copied from disk to tape. (I have a permanent archive on tape now, *and* a recent cold backup for faster recovery if the last backup was good.) Both databases are now backed up and restarted by 1:15.

If minimum downtime is essential, backup to disk first, even if you have to buy another disk drive *dedicated* to that purpose. Disks are cheap these days; lost productivity and/or sales due to downtime are not.

-- 
Tim Irvin, HP-UX System Administrator / Oracle DBA
Lockheed Martin Missiles and Space, Sunnyvale, California
e-mail: irvin_at_lmsc.lockheed.com    voice:  (408) 742-0440
************ all standard disclaimers apply ************
Received on Mon Sep 09 1996 - 00:00:00 CEST

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