Enabling an Old Data File

[tekdudedude]

Hello,

I have an old schema where I have the datafile but no RMAN backup or export.

What would be the process to re-online the corresponding tablespace and re-create the schema in a way that Oracle is happy with.

Because this tablespace is old and beyond the archive log and RMAN retention period it may not be as easy as alter tablespace mytablespace online.

What can you recommend?

Thanks,

TD

 

[Turkbear]

Hi,
It may not be possible since, unless that was the ONLY datafile from the old schema, the data may not be complete - even if it is, the header information will no longer be applicable so the database instance (with its control file unaware of that datafile) will have no way to access the data.

Perhaps SantaMufasa has some tricks up his sleeve that he will share??





To Paraphrase:"The Help you get is proportional to the Help you give.."

 

[LKBrwnDBA]

Even if you have the data in a data file, it's of no use without the "metadata" which is not included in that backup.


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The person who says it can't be done should not interrupt the person doing it. -- Chinese proverb

 

[SantaMufasa]

Perhaps SantaMufasa has some tricks up his sleeve that he will share

If I had those kinds of tricks, I would be a rich Santa. I wish I had some type of magic for you, TekDude[sup]2[/sup].

Mufasa
(aka Dave of Sandy, Utah, USA)
[I provide low-cost, remote Database Administration services: www.dasages.com]

 

[karluk]

There is no documented way to recover the data in the old datafile without also having at least a contemporaneous copy of the datafile(s) for the system tablespace.

But that doesn't mean you should give up. I would be quite surprised if Oracle support doesn't have a utility which can scan through a datafile and attempt to interpret the data it contains. You should contact Oracle and ask them if they can help. You would need something like the dbv (dbverify) utility, but with much more sophisticated output.

 

[SantaMufasa]

Yes, I wholeheartedly agree with Karl...Oracle Consulting Services (OCS) have tools that are only available via a consult with them. We engaged OCS a couple of years back to try to recover data from a corrupted tablespace. And, yes, they had tools to salvage a significant portion of the data.


Mufasa
(aka Dave of Sandy, Utah, USA)
[I provide low-cost, remote Database Administration services: www.dasages.com]

 

[tekdudedude]

Thanks guys. I was able to retrieve the data required from an old export.

But ya know, the more I worked with it and thought about it, the more I was intrigued about trying to achieve this. You could learn a lot about Oracle internals I think if this could be achieved. OCS can't save all the fun for themselves!

Thanks again guys for the responses,

TD