Thursday, July 15, 2010

Tips To Solve 'ora-1578' Error'

Data in an Oracle database is stored in logical units called blocks (also called, logical blocks or data blocks). This is the finest level of database allocation in Oracle. However, if it gets corrupted, it can cause serious data loss. The common reason of block corruption are, operating system issues, Oracle problems, defective I/O hardware, and recovery attempts from 'NOLOGGING' or 'UNRECOVERABLE' database actions. A corrupted Oracle database is generally not accessible by the user and thus necessitates you to either restore it from backup or Repair Oracle Database.

To exemplify such problems of data blocks corruption, consider the following issue. Suppose you are an Oracle administrator and have an important database that contains relevant information. But, suddenly when you try to access this database, you encounter the below mentioned error message:

ORA-1578

The error doesn't show any additional information about the cause and behavior of database issue.

Cause:

'ORA-1578' occurs when the data blocks of Oracle database are marked as corrupt. In this specific case, it has occurred because the NOLOGGING' or 'UNRECOVERABLE' database operation has been performed on its object(s) and the file containing this data has been subsequently recovered. This sequence of events ultimately results in corruption of blocks that have been affected by these operations.

Solution:

  • You should follow the below sequence of steps to recover from such problems:
  • You need to first determine the objects that have been affected due to corruption

If the database exists in ARCHIVELOG mode, a good backup of affected data files is available, and all the ARCHIVELOGS until the current time are available (from the time of first backup), you should go for a complete database recovery. However, if only the temporary tablespace is affected, no user action is required.

Alternatively, you can use COLD backup or an existing export file to restore the database.
If none of the above solutions works for you, it is suggested to use a third-party utility to oracle database recovery. These are exclusive Oracle database repair tools designed to Repair Oracle Database and restore its data to a secure location without changing its contents.

Oracle Recovery software is a high-end tool that repairs corrupted Oracle database and restores all database objects like, tables, views, cluster tables, and more to a secure location. The oracle database repair software employs risk-free scanning algorithms to Recover Oracle Database. Supporting Oracle 9i, this utility has a user-friendly interface for easy working.


No comments:

Post a Comment