Author Box
Articles Categories
All Categories
Articles Resources

How to Easily Approach and Circumvent Data Block Corruptions in Oracle

April 17, 2012 | Comments: 0 | Views: 225

Corruption manifests itself in an Oracle database in primarily two forms. An Oracle data block may contain an invalid header or the contents of the block could be logically inconsistent. In both the above cases, you might face terrible loss of information, including application and user data, Oracle control information, etc. Oracle provides you a comprehensive list of solutions to deal with such instances. You can configure different parameters ('DB_BLOCK_CHECKING', 'DB_BLOCK_CHECKSUM', etc.) on your database to detect corruption. The Oracle Recovery Manager (RMAN) enables you to implement a database backup and recovery plan. However, if these methods fail to work, you can use third-party Oracle recovery software to recover your lost or damaged database objects.

For instance, when you start Oracle, you may receive the following error:

'ORA-01092: ORACLE Instance terminated. Disconnected forced'

If you examine your alert log at this stage, you may encounter a few more errors:

'ORA-01578: ORACLE data block corrupted (file # 1, block # 57371)'


'ORA-01110: data file 1: 'G:\ORACLE\PRODUCT\10.1.0\ORADATA\HRDEV\SYSTEM01.DBF''

The error reveals occurrence of a possible block corruption in your Oracle database that has resulted in an unexpected shutdown of the Oracle instance. This is generally caused due to various factors, such as bad permissions, missing data files, or OS related issues, etc.

In order to confirm about block corruption, you should run the external command-line utility 'DB_VERIFY' on the suspected file. If the output shows errors in the same page locations, you can try to fix corruption using any of the given methods:

  • You can try to drop and recreate the damaged object, if you are not worried about data loss. You can get back all your lost data from the external sources. To identify which objects are corrupt, run the following query:

'select tablespace_name, segment_type, owner,


from dba_extents

where file_id = <corrupted file id>

and <Block #> between block_id AND block_id + blocks-1'

This query maps the physical file location to the corrupt objects.

  • Restoring data from backup is a more reliable way to get back everything stored in all good blocks inside the file.
  • You should leave 'DBMS_REPAIR' as the last resort to deal with block corruption. It can help you identify and repair corruption in your Oracle database.

If you again see the same errors on your database, you should take help of professional Oracle database recovery software. These tools efficiently repair corrupt DBF files to restore all damaged or inaccessible database objects, such as tables, views, procedures, triggers, functions, etc. They search for Oracle databases in your system and allow you perform a selective recovery of database components.

Mark willium is a database recovery specialist. He has written several articles on Oracle database recovery topic. You can check all those articles at

Source: EzineArticles
Was this Helpful ?

Rate this Article

Article Tags:

Block Corruptions


Oracle Recovery


Oracle Database Recovery


Recover Oracle


Repair Oracle Database

Windows 8 will change the way you work and play, says Microsoft and we agree. Nearly all of the previous iterations of the Windows OS have been evolutionary but Windows 8 is set to change all that.

By: Sakshi Sharma l Computers & Technology > Mobile Computing l April 03, 2013 lViews: 662

Many antivirus programs available today have various features but it entirely depends on the user to make the best choice from among these different computer virus protection programs online. Before

By: Alex l Computers & Technology > Software l December 28, 2012 lViews: 370

You can add a new color to your entertainment life with iskysoft video converter for mac & iskysoft dvd creator for mac and make your Christmas holidays all the more special. iskysoft video

By: Zaithyn Galter l Computers & Technology > Software l December 23, 2012 lViews: 1070

The choices you make regarding the type of recruiting software you choose to use are important. Being an informed consumer is essential to getting a system or components that complement systems of

By: Maria Warne l Computers & Technology > Software l December 14, 2012 lViews: 306

The Cisco certification has become the most popular IT training in recent days and it offers three different levels of these certifications include as: associate, professional and expert-level.

By: sandidas chakma l Computers & Technology > Certification Tests l December 11, 2012 lViews: 237

Millions of prospective 12th standard students are gearing up their preparations for the Joint Entrance Exam for engineering seats. From 2013, it has been decided by the IITs, CBSE, JEE organizing

By: Sarkariexam l Computers & Technology > Certification Tests l December 07, 2012 lViews: 633

Hard drive failure sucks, no matter how you look at it. But it isn't the end of the world, as long as you avoid these three deadly mistakes.

By: Maureen Daviesl Computers & Technology > Data Recoveryl April 17, 2012 lViews: 209

We all buy insurance, for our homes, our cars, and our businesses. Being prepared for disaster, whether natural or otherwise, is just the smart thing to do. It's also smart to be prepared for a data

By: Joe Sallandl Computers & Technology > Data Recoveryl April 16, 2012 lViews: 189

Your business does not have to suffer due to the vagaries of Mother Nature. Well designed and implemented data management strategies and techniques from your IT services provider are just the ticket

By: Joe Sallandl Computers & Technology > Data Recoveryl April 16, 2012 lViews: 180

How safe is your business in the aftermath of fire or any other catastrophe in terms of your IT systems? Most businesses have an emergency plan of evacuation in the event of a fire, however many do

By: Steve R Bryanl Computers & Technology > Data Recoveryl April 16, 2012 lViews: 192

Digital document archiving is a more secure, efficient, and sustainable way of maintaining your valuable files and official documents. Learn the benefits of using this modern system and digitize all

By: Lyle Osbornel Computers & Technology > Data Recoveryl April 15, 2012 lViews: 169

  Your personal digital collection includes a horde of photos, songs, videos, documents, and programs among other things that you access and/or run every day on your computer. At the same time, you

By: Gaurav Srivastaval Computers & Technology > Data Recoveryl April 13, 2012 lViews: 202

MySQL is an open source database management system and is popularly used by many small as well as large scale business houses. For its compatibility with C, C++, JAVA, PHP and PERL languages, it is

By: Mark Williuml Computers & Technology > Data Recoveryl April 10, 2012 lViews: 154

Discuss this Article

comments powered by Disqus