CORRUPT A DATABASE

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CORRUPT A DATABASE

kerusy

Ten Centuries

Points: 1107
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January 21, 2009 at 6:23 am

#199048

Hello guyz! Am doing some research on database repair, and i need to have a corrupt database, inorder for me to use the DBCC commands and verify their working. Any help on this please?

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steveb. SSC-Forever Points: 46733 More actions · Answer 1

there are databases linked here that are in various stages on corruption.

http://sqlskills.com/BLOGS/PAUL/category/Corruption.aspx

CrazyMan SSChampion Points: 12560 More actions · Answer 2

Interesting Question, Search Google, to start with play with sys tables, this should do the trick :D, make sure that you do this in a test environment or may be better on your local machine

Gail Shaw SSC Guru Points: 1004504 More actions · Answer 3

Disclaimer: Do not do this on a production server. Do not do this to any database that you care about. If you want to play, do so on a SQL instance installed on your workstation.

Right, now that's out of the way...

Take the database offline, open the mdf file in a hex editor. Go to an offset 40k or so into the file (to avoid the critical header pages) and then 0 out a block of data. Save the file, close it, go back to SQL and attempt to bring the database online

I say attempt, because last time I tried that, I fried the DB so badly that SQL couldn't bring it back online.

Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

Paul Randal One Orange Chip Points: 29544 More actions · Answer 4

See http://www.sqlskills.com/BLOGS/PAUL/post/Conference-corruption-demo-scripts-and-example-corrupt-databases.aspx for a bunch of pre-corrupted databases.

Also see http://www.sqlskills.com/BLOGS/PAUL/post/Example-20002005-corrupt-databases-and-some-more-info-on-backup-restore-page-checksums-and-IO-errors.aspx

Paul Randal
CEO, SQLskills.com: Check out SQLskills online training!
Blog:www.SQLskills.com/blogs/paul Twitter: @PaulRandal
SQL MVP, Microsoft RD, Contributing Editor of TechNet Magazine
Author of DBCC CHECKDB/repair (and other Storage Engine) code of SQL Server 2005

Jeff Moden SSC Guru Points: 1004414 More actions · Answer 5

Heh... just tell it to run for office. 😛

--Jeff Moden

RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)

The_SQL_DBA SSChampion Points: 10494 More actions · Answer 6

If you wanna corrupt it time and again after you try repairing then backup the clean database before you start corrupting it..

Thanks!!

The_SQL_DBA
MCTS

"Quality is never an accident; it is always the result of high intention, sincere effort, intelligent direction and skillful execution; it represents the wise choice of many alternatives."