Recovering unmountable Oracle 9i database

The instance of an Oracle server is assembled using allocated memory (System Global Area) and running process (SMON, PMON, LGWR, DBWR). When you start the Server instance, it is allocated with the particular database, which is known as the mounting the Oracle database. This is the most primitive step of using the database and its related records. However, at times you are unable to access the Oracle instance. Such problems may occur due to corruption in Oracle database, which can happen because of various reasons such as media block corruption, damaged file system, damage in the Oracle 9i application server, etc. In such cases, you should try out each and every possible workaround to recover Oracle database including using latest database backup. If you are unable to fix the error, then you should use a third-party Oracle database recovery software to do the needful.

Consider a scenario wherein you are having Oracle 9i server on your Windows Server 2003 system. You try to mount the Oracle database using the following command:

oradim -new -sid %ORACLE_SID% -pfile c:xyz.ora

However, you are unable to mount the database instance. An erro message is displayed suggesting that the database cannot be mounted.

Cause:

There could be the following causes for the aforementioned problem:

You may not have the appropriate credentials to log into the database server and mount the database.
You are unable to open the parameter file.
The database has corrupted due to any of the reasons mentioned earlier in this article.

Resolution:

To resolve this problem, you need to repair Oracle database. To do this, you would have to ensure the following precautions:

You have the appropriate credentials to log into the database server.
The parameter file is at its mentioned location.
Try to find out if the backup of the database is clean and updated. If yes, then you should restore the database with its backup.
You should use the DBMS_REPAIR method to repair the block corruption in the Oracle database.

However, if you are still not able to mount the Oracle database then you should use a third-party DBF recovery software. Such read-only tools are able to recover DBF files without overwriting the existing database.

Stellar Phoenix Oracle Database Recovery is an Oracle database recovery software that repairs Oracle database created in Oracle 9i. It is capable of recovering various database components such as tables, views, cluster tables, schemas, sequences, etc. In addition, this oracle recovery software restores primary and foreign keys associated with the database tables. It is compatible with Windows Server 2003 and XP.

Resource: http://www.americanchronicle.com/articles/view/204324

Oracle Recovery when Oracle Display Error 00376

In Oracle database system, the data is saved in the form of a DBF (Database File) file. It is saved in a hierarchy at four distinct levels: tablespace, segments, extents, and blocks, in the ascending order. When database corruption occurs, it usually happens at the lowest level, that is the at the tablespaces. Due to database corruption, you are unable to mount the database thereby making it inaccessible, which is a very undesirable proposition. Such instances occur due to various reasons such as virus infections, database header corruption, file system corruption, media block corruption, etc. In such situations, you should try to repair Oracle database using appropriate corrective measures. However, if you are unable to perform DBF recovery then you should use a third-party Oracle recovery software to do the needful for you.

Consider a scenario wherein you try to mount an Oracle 9i database but fail to do so. An error message is displayed, that is:

"ORA-00376: file xx cannot be read at this time"

Cause:

The primary cause of this error message is that the UNDO tablespace has corrupted. Because of this, you are unable to mount the database. Also, you would get the same error message every time you try to mount the database.

Resolution:

To resolve this tricky situation, you should try to repair Oracle database. To do this, you can perform either of the following steps:


Change the undo_management parameter from 'Auto' to 'Manual'.

Create a new UNDO tablespace.

Drop the previous UNDO tablespace.

Now try to mount the database. It should run fine now.

However, sometimes dropping the damaged tablespace can be troublesome and it would generate the following error message:

" ORA-00376: file string cannot be read at this time"

In such situations, you should use a third-party Oracle database recovery software to recover the corrupted database. Such DBF recovery tools are able to recover DBF files without overwriting the existing database.

Stellar Phoenix Oracle Database Recovery is an Oracle database recovery software that is able to repair corrupted Oracle databases from all instances of logical corruption. It is specifically designed to recover Oracle database created in Oracle 9i. This Oracle database recovery utility restores several database components such as tables, cluster tables, schemas, views, sequences, etc. In addition, this DBF recovery tool is able to recover the user-defined data functions and packages & packages body as well. It is compatible with Windows Server 2003 and XP.This article is refereed from http://www.americanchronicle.com/articles/view/203418

Avoid Common Mistakes While Recovering Damaged Oracle Database

Database corruption is a quite common problem in every Relational Database Management System, including Oracle. The corruption makes your database inaccessible, because it cannot be recognized by Oracle application. In a number of database corruption situations, DBA (Database Administrator) can restore the database. However, in some cases, the database administrator may make some serious errors that can lead to further corruption. Such mistakes are generally caused by poor judgment and stress. In such situations, Oracle database recovery solutions come for your help.

Following are two general issues that you should avoid while handling a damaged Oracle database:

Backup Failed Oracle Database- The very first step that you must take in such cases, is to backup the corrupted Oracle database. Unfortunately, several Oracle versions don't test the recoveries, and if you discover the backups aren't recoverable, you might be happy to see that you have a complete backup of the corrupted Oracle database.


Rarely Force Bad Recovery- If you are unable to repair Oracle database (DBF) file, it cannot be opened. It is the way of Oracle application to prevent further damage due to manual repair of the database. You can use the below options to open a recovered database:

Use an earlier backup- This is quite useful to have an updated backup to easily cure database corruption.

Restore initially failed Oracle database- It might take less time to manually repair the database than forcing bad recovery.

Force to open database- You should use this option as a last resort only. It may cause massive damage to the Oracle database and permanent data loss.

You should always consult the experts and take best practices to ensure perfect recovery of damaged Oracle database. A minor mistake, while handling a damaged Oracle database may cause serious corruption and severe data loss.

In order to prevent such critical situations from being occurred with your Oracle database, you should maintain an absolute backup. The backup must be updated regularly and it should be checked for validity. If backup itself gets damaged, oracle database repair is the only way to go for.

Oracle database recovery is best possible using powerful and advanced third-party applications, which successfully recover Oracle database in all possible cases of database corruption. They deploy high-end scanning mechanisms for assured recovery of all database objects.

Stellar Oracle Recovery is the most excellent solution to effectively handle all your Oracle database corruption problems. It works well with Oracle 9. The oracle database recovery software is capable of restoring all the Oracle database objects, such as tables, reports, forms, macros, data types, constraints, and more.

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Oracle Database Recovery from its Backups

Recovery and backup are the most important aspects of database job. If anyone lose their company's data, he/she could very well lose his/her job. Software and hardware can always be replaced but data may not be replaceable. For smooth functioning of any organization/company good recovery and backup technique is required. You can schedule your backup policy on daily, weekly or monthly basis. Consider a situation, you are working on the company project and your database gets corrupted and backup is not managed, at that situation you should use an advanced database recovery software to recover database.


Backup frequency of any database normally depend upon the given below factors:

Criticality of the data/ Value of the data to the organization. Rate of data change/ transaction rate. Read-only tablespace needs backup just once right after you make it read-only. If you are running in archivelog mode you can backup parts of a database over an extended cycle of periods. Etc.

Oracle Database Backing-up strategies: Various strategies are available for backing-up of Oracle database.

Export/Import: Export is the logical database backup in which they extract logical definitions and data from the database to a file.

Off-line Backup: It is also known as cold backup. Shutdown the database and backup all the logs, control files and data.

On-line Backup: It is also known as hot backup. If the database is in ARCHIVELOG mode, set the tablespaces into backup mode and backup their files.

RMAN Backup: RMAN utility is used to backup database while database is in off-line or online mode.


Difference between online and offline backup: There are so many difference between online and offline backup. Some of them is given below:

Online backup is performed when database is open and available for the user while offline backup is performed wher database is unavailable for its users. It is easier to restore from the offline backup than online backup. Point-in-time recovery method is available in the online backup while it is unavailable in the offline backup.

Your Oracle database got damaged and none of above backups are available, you could use stellar oracle database recovery software to recover your database. This software is read only in nature. This Oracle recovery software completely repairs and restores all Oracle database objects, such as tables, table spaces, schemas, views, roles, constrains, indexes and sequences.

Resolving "ORA-01145: offline immediate disallowed..." Error

A DBA (Database Administrator) encounters numerous error messages while working on a production database. These error message are mainly related to network trouble, problem with instances, or database corruption. While network and instance jobs can be handled easily, the database corruption error message is very difficult to surmount. Few main causes for Oracle database corruption are Oracle bugs, virus hit, unsupported disk repair applications, and damaged hardware. After an Oracle database corruption error message appears, the instance does start further rendering to inaccessibility of saved data. In such cases, if a DBA has created complete backup of the database, then s/he has nothing to worry. However, if no backup exists, then the DBA needs to search for an effective third-party Oracle Database Recovery application.

To elaborate the above case, consider a practical case, wherein you have Oracle 9i database (Employee) on your Windows XP machine. The database is in NONARCHIVELOG mode and all the records are stored in SYSTEM tablespace. When you try to run a SQL command to access the records saved in the Employee database, you encounter the below error message:

"ORA-01145: offline immediate disallowed unless media recovery enabled."

After the above error message appears, the Employee database records become inaccessible.


Cause:

The above error message pops up when UNDOTBS01.dbf is corrupted.

Resolution:

To get rid of the above error message and to access the Employee database records, you will need to restore from a cold backup. However, doing so means that you will have to loose all your updated data. In such cases, if you want to save your data and repair Oracle database, then you will need to opt for an effective Oracle Recovery utility.

An oracle database repair application repairs logically corrupt databases in a few easy steps. The repaired database is in reusable state and can also be saved at your preferred destination. The highly advanced recovery mechanism to recover Oracle database ensures complete and maximum recovery, without making any changes in the original database. Easily downloadable from the Internet, these tools can be used by any database user.

Stellar Oracle Database Recovery is an extremely powerful Oracle database recovery application that recovers all logically corrupt databases created in Oracle 9i. With recovery of almost all Oracle database objects, tables, schemas, indexes, and more, the recovery tool can recover Oracle database irrespective of its cause of corruption.

Recovering Inaccessible Oracle Database Using an Oracle Database Recovery Tool

When you start an Oracle instance, it is allocated with a particular database, which is also known as mounting the database. By mounting the it, you can access and work (create, modify, or delete) on that particular database. But you may have noticed that you are unable to mount the selected database on several occasions because of different types of reasons. Some of the reasons could be corruption (because of file header corruption, abrupt system shutdown, virus infections, etc), or improper login credentials, among other reasons. You should look to address the problem according to the particular reasons. If corruption is the root cause of the inaccessible, then you should use repair Oracle database using appropriate methods failing which you must use a professional Oracle recovery software.

Let us assume a real-life scenario in which you are trying to mount an Oracle with the credentials of a database administrator, using the following command:

"oradim -new -sid %ORACLE_SID% -pfile c:\path\to\your\init.ora"

But when the command is run, the database instance does not start leaving the database in a vulnerable state.

Cause:

Such problematic situation can appear because of the following reasons:

The parameter file specified in the command cannot be opened.
You do not have the proper credentials to start and run the database instance.
The database (.DBF) file is damaged, which is why you are unable to open the database.

Resolution:

To address this problem and start the database instance, you can perform the following corrective measures:

Check and verify the parameters given in the command. Also, you should check that the parameter file is at its default location.
Make sure that you have proper rights to open and start the database instance. Try to start the instance after checking the rights.
If the previous methods do not work, you should restore it with its clean and updated backup.

If you are still unable to open the database instance, then that means the DBF file is critically damaged. You should take the services of a third-party Oracle database recovery software to resolve such issues. These database recovery tools are able to recover Oracle database and bring it to a usable state with the help of fast and sophisticated scanning algorithms.

The most reliable DBF recovery software is Stellar Phoenix Oracle Recovery, which supports recovery of Oracle created in Oracle 9i, 10g, and 11g. With the ability to recover DBF files by restoring various components including tables, views, tablespaces, synonyms, indexes, sequences, etc, this Oracle database recovery utility is compatible with Windows Server 2003 and XP.

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Oracle Database Recovery Methods

Oracle database is a relational database management system which is also known as Oracle RDBMS. Oracle RDBMS is developed by the Oracle corporation for the storing of data. Oracle database stores data phisically in the form of data files and logically in the form of tablespace. Tablespace of the oracle database contains various types memory segments some of them are index segments, data segments and many more. Sometimes tablespace of oracle database gets corrupted that cause database goes in inaccessible mode. To overcome this problem you will need a third party advanced oracle database recovery software.

Cause:

There are various causes for the oracle database corrupted. Some of them are given below:

Virus Attack: Virus attack may be the cause of corruption. To avoid this problem use an advanced anti virus program in your system.

Automatic System Shutdown: Automatic system shutdown is also affect the proper functioning of your database. To overcome these types of problems always use a power backup.

Concurrency: Multiple operation on the same database instance may also affect the database that cause database gets damaged.

There are three types of oracle recovery methods used by the database administrator to recover the corrupted oracle database. Which are given below:

Instance Recovery Method
Crash recovery Method
Media Recovery Method

Instance Recovery Method : Oracle database performs this recovery method automatically at the instance startup. This method occurs in an open database when one instance of database discovers another instance of database has crashed.

Crash Recovery Method : This recovery method also perform automatically at the instance startup. Crash recovery method occurs when either a single database instance or all database instance has corrupted.

Media Recovery Method : Unlike above two recovery methods this recovery method require you to issue the command.

Stellar Oracle Database Recovery software repairs damaged oracle 9i, 10g and 11g and recovers objects of oracle database like table spaces, tables, synonyms indexes and sequences. This oracle recovery software is designed for the window XP and 2003 operating system. You can see the preview of your recoved database with the help of demo version of the software.