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Data missing [message #606556]

Sun, 26 January 2014 15:44

Jack14
Messages: 497
Registered: December 2011
Location: INDIA

Senior Member

Hi,

Customer complaint that there seem to have lot of data missing in database.When they checked the data in the month of december,
there was 50,000 transaction data but when they check now , they found only smaller amount of data.

Can you help me to find how data is missing and how to recover those missing data ?

Thanks,
Jack

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Re: Data missing [message #606558 is a reply to message #606556]

Sun, 26 January 2014 16:11

BlackSwan
Messages: 26766
Registered: January 2009
Location: SoCal

Senior Member

You will need use DBMS_LOGMNR against all Archived REDO logfiles between 1 December 2013 & now to see what DML occurred against relevant table(s).

Please read and follow the forum guidelines, to enable us to help you:

http://www.orafaq.com/forum/t/88153/0/

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Re: Data missing [message #606573 is a reply to message #606558]

Mon, 27 January 2014 02:48

cookiemonster
Messages: 13966
Registered: September 2008
Location: Rainy Manchester

Senior Member

You could check the application code to see what would delete the missing data and then work out the circumstances in which that code would have been run.
Of course if the data was deleted manually (hand written delete statement) and you don't have auditing then Blackswan's suggestion is your only option.

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Re: Data missing [message #606577 is a reply to message #606556]

Mon, 27 January 2014 03:14

John Watson
Messages: 8974
Registered: January 2010
Location: Global Village

Senior Member

To use the log miner from 1 December to now (57 days) would be a massive task, and to be honest I think you may find it impossible. Just restoring the archive logfiles might be a problem, never mind populating and querying v$logmnr_contents.
I would try to narrow down the time frame first. Do a tablespace point in time recovery to 28 days ago. Are the rows there? Then do another TSPITR to 14 days before or after, depending. Then another. That will bring the time frame for the error down to 7 days, which makes the log miner a bit (not much) more feasible.
Of course, you'll need to do all this against a clone database.
You had better make you client aware that this will be an expensive operation with no guarantee of success.

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Re: Data missing [message #606590 is a reply to message #606577]

Mon, 27 January 2014 03:45

ThomasG
Messages: 3212
Registered: April 2005
Location: Heilbronn, Germany

Senior Member

The first thing I would check is whether the actual data is really gone from the DB.

In 9 out of 10 cases when someone calls me with a panicked "the data is gone!!!!" they just have some soft of additional filter set in their frontend, or some mix-up in their query, etc....

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Re: Data missing [message #606595 is a reply to message #606590]

Mon, 27 January 2014 04:14

gazzag
Messages: 1119
Registered: November 2010
Location: Bedwas, UK

Senior Member

To reiterate what ThomasG said, are you sure that your customer is even looking at the right database? In my experience DBAs, managers, users, customers, etc. can all call the same thing something different. If possible get them to log into the database and confirm that you can see their session using SQL*Plus. I had a similar experience with a customer who was logged into a test copy of the database by mistake.

HTH
-g

[edit: typo]

[Updated on: Mon, 27 January 2014 04:31]

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Re: Data missing [message #606642 is a reply to message #606595]

Mon, 27 January 2014 13:41

Jack14
Messages: 497
Registered: December 2011
Location: INDIA

Senior Member

Thank you all for your suggestions.

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