Re-organising a database?

From: Tim Kearsley <tim.kearsley_at_milton-keynes.gov.uk>
Date: 14 Apr 2003 02:19:22 -0700
Message-ID: <725736ef.0304140119.6623ab37@posting.google.com>

Hi all,

Environment is:

Oracle 8.1.7 on AIX 4.3.3 on RS6000 SP hardware

I've got a legacy database, about 30 Gbytes in size, which I would very much like to re-organise. Primarily I would like to implement LMTs and to put the datafiles into a structure which is fairly close to OFA.

The obvious solution I suppose is to create the new database and export/import from the existing one. My problem is the time this appears to be taking. A trial took some two days by the time I had imported, re-created indices and solved a few problems with invalid packages. The database is pretty heavily used and it is going to be hard for me to sell a weekend's downtime to the users.

Are there any other techniques I could use to reduce this downtime? I admit that I haven't tried tuning the export/import process. At present the export is done to a Unix pipe which compresses the dump file on the fly. Likewise the trial import was done by uncompressing the dump file on the fly. Is it likely to be substantially faster to export to multiple files rather than compressing (I am facing an OS filesize limit)?

Any thoughts or ideas very welcome.

Thank you.

Tim Kearsley
Database Manager
Milton Keynes Council Received on Mon Apr 14 2003 - 04:19:22 CDT