Shulou(Shulou.com)06/01 Report--

1. Introduction of Oracle database system:

ORACLE database system is a group of software products with distributed database as the core provided by ORACLE (Oracle). It is one of the most popular client / server (CLIENT/SERVER) or Bhand S architecture databases. For example, SilverStream is a kind of middleware based on database. ORACLE database is the most widely used database management system in the world. As a general database system, it has complete data management function and as a relational database.

2. Fault description of Oracle database system:

1. After communicating with the user, when the user uses the database in error, the error shows that "system01.dbf needs more recovery to maintain consistency, and the database cannot be opened".

2. After the engineer inspects the database file, it is found that sysaux01.dbf has bad blocks. Because the user does not make a backup to the database, the database cannot be restored through the backup. After further communication with the user, the user provides all the files in the oraclehome directory of the database, and there is an urgent need to restore the data under the zxfg user.

Third, fault analysis of Oracle database system:

1. Through the error report of the database, we can preliminarily judge that the cause of the failure may be the damage of the control file, the damage of the data file, the inconsistency of the SCN between the data file and the control file, and so on.

2. Through further detection and analysis of the database file, it is found that there are bad blocks in the sysaux01.dbf file. After repairing the number and starting the database, many queries reported errors, export and data pump tools could not be used, query alarm logs, analysis of errors, due to sysaux file damage, resulting in appeal errors.

3. The database cannot be repaired from the database level. The data files of system and user tablespaces are normal, and the underlying parsing data files can be used to recover user data.

4. The fault recovery process of Oracle database system:

1 use DBV to detect data files

The analysis results show that 40 pages of SYSAUX01.DBF file data block (Data) failed, 29 pages of index page (Index) failed, and other files were detected normally.

2 repair the database and open the database

3 query database reported error, export and data pump reported error

Make various attempts and consult a large amount of data. This internal error in the database cannot be fixed by command.

4 low-level parsing to import ZXFG user's data into the new database

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