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ORACLE DBF Data Recovery ??
Could someone please suggest if it's and how it's possible to recover data from DBF files if oracle tablespace can't be run ??
I read a lot of mails,articles etc ... regarding how to and when , but just got from one error to another ....
Here is what happened ...:
We have Oracle 10.2.0.1 which is 90Gb big and is in 5 files ..... OS is linux ...
Due to some optimization testing we made a backup copy of our /HOME dir on linux ..... but the guys who did the copy job ,missed out that the 5th DBF file had a link to the original file which was outside of our /HOME ... so the original file was not copied just link
So when we run the backup copy .... Oracle was working ok .... we did some tests , some truncation of one tabel .... but after a few hours we decided to stick with our original db ....
When we then tried to run the original db , we failed ..... the first error was "Oracle in shutdown ......etc..." .... then we shutdon unmount, mount and got the real error :" Inconsisstency with log files for this 5th file " .....
So what happened is that the 5th file , because of the link .... was never copied like the other 4 BUT was used at first with our original DB and then used also with our backup DB (ofcourse DBs were identical at that time)... and because we did some table truncation, the 5th file the file was changed ....
I know we lost data from our 5th file .....So now the question is " How can we get data from our first 4 files " ?? So that we at least get something out of it ? Is there any software available for extraction of "corrupted" data from dbf files ?
It will run, but that is meant for dropping the tablespace after u open the database. U can also take the datafile offline and try to open the database, but I do not know if you will be able to read all tables in the tablespace, you should probably export the tables anyway.
Here are a few links that might help.
1. use DUL, I do not have experience with it, so u have to do some research.
2. Open the database by setting the ALLOWRESETLOGS_CORRUPTION=TRUE in the init.ora. But there is no 100% guarantee that we can open the database. However, once the database is opened, then you must immediately rebuild the database. Database rebuild means: perform a full-database export, create a new and separate database, and import the recent export dump.
[http://www.dbspecialists.com/files/presentations/missing_logs.html]
3. Third, but it should be first, if u have Oracle Support, call them