Re: Why export is not a good archiving tool

From: Vladimir M. Zakharychev <>
Date: Tue, 18 May 2010 02:49:17 -0700 (PDT)
Message-ID: <>

On May 18, 2:43 am, "" <> wrote:
> I need to know why exporting a database periodically is not a suitable
> method for preserve access to historical data.  A customer with 10-20
> year retentions is using this to "preserve access" for compliance
> reasons.  I would like to push them towards IBM Optim, Outerbay,
> Solix, etc. but I don't know how to explain the shortcomings of their
> method.  Apparently the existing records don't have a nice date field
> to identify old data and leaving it in place doesn't protect it from
> damage or loss.

As others pointed out, exports are no substitute for proper backups. However they might do for data retention policy compliance if done properly: taken in CONSISTENT mode, labeled with a timestamp, signed with a public key or at least SHA-1 hash and stored on durable WORM media, like DVD-R, in several vaults across the country. ;)

The good thing about exports is that you can do partial exports (only the data you want) and partial imports (just the tables you want,) so if you want to dig for just a few rows from a couple of tables you might be able to restore them pretty fast into any available database whereas doing full database restore might take much longer and will require you to create new Oracle instance using Oracle software version that was in use back then or at least backwards-compatible with it (imagine you need to do this 15 years later - you will need to find proper Oracle software distribution and then find a compatible OS that can run it on compatible hardware or VM.)

However, considering that export/import functionality evolves over time, too (EXP/IMP are already deprecated in favor of DataPump for example,) you might be even better off taking data dumps into some database-independent format (like flat files that could be loaded using any bulk-loading tool into any database that would be in use 15 years from now,) compressing, encrypting and signing these dumps to protect them from tampering with or unauthorized access and storing them on reliable WORM media. Not sure it's going to be cheaper that IBM Optim, Solix or HP IAP, and certainly not that convenient, but it's nevertheless an option.

My $0,02.


   Vladimir M. Zakharychev
   N-Networks, makers of Dynamic PSP(tm) Received on Tue May 18 2010 - 04:49:17 CDT

Original text of this message