Using the Dbverify tool in Oracle

Data block corruption due to hardware failure or operating system failure during Oracle database operation that causes Oracle to not recognize or contain content in Oracle format

Failure, this bad block can be divided into media damage and logical corruption. A block check is given below, and a block check is implemented using the Dbverify tool.

First, block inspection

1. When to check the block

When a block of data is read or written, the block is checked for consistency, and the contents of the check include

Version of The Block

Compare blocks in cache and block buffer with data block addresses

Verify on request (checksum)

2. Error tips for damaged blocks of data

You can find this error hint from the alert log file and give a similar hint when a corrupted block of data is found in the session

Ora-01578:oracle data Block corrupted (file # 6, Block # 11)

Ora-01110:data file 6: '/U01/APP/ORACLE/ORADATA/ORCL/TBS01.DBF '

3. Related characteristics of block damage (several inspection tools)

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Attribute bad block reconnaissance type can repair damaged blocks

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Dbverify Physical No

ANALYZE Logic No

Db_block_checking Logic No

Db_block_checksum Physical No

Exp Physical No

Flashback logic is

Dbms_repair Logic is

Block Media recovery Unknown is

Ii. Introduction of Dbverify Tools

Characteristics

is an external program that runs at the operating system prompt to validate data files and check block consistency errors

Only for data files, can verify the open phase of the data file and shutdown state of the data file

You can verify a replicated data file, or you can verify a mirrored copy of a backup

No support for online log files, control files, archive logs, Rman backup set validation

The validated file can be located on the file system, ASM disk or original device

Located in Unix systems: $ORACLE _HOME/BIN/DBV

Located in the Windows system:%oracle_home%/bin/dbv.exe

For the Dbverify tool, the high version can automatically identify the lower version of the database, such as 11g DBV access to 9i of the database, but the lower version of DBV access to the high version of the error

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