10
Offline Database Verification Utility

This chapter describes how to use the off-line database verification utility, DB_VERIFY. The chapter includes the following topics:

Functionality
Restrictions
Usage
- Command-Line Syntax
- Parameters
Server Manager Compatibility

DB_VERIFY

DB_VERIFY is an external command-line utility that performs a physical data structure integrity check on an offline database. It can be used against backup files and online files (or pieces of files). You use DB_VERIFY primarily when you need to insure that a backup database (or datafile) is valid before it is restored or as a diagnostic aid when you have encountered data corruption problems.

Because DB_VERIFY can be run against an offline database, integrity checks are significantly faster.

Additional Information: The name and location of DB_VERIFY is dependent on your operating system (for example, dbv on Sun/Sequent systems). See your operating system-specific Oracle documentation for the location of DB_VERIFY for your system.

Restrictions

DB_VERIFY checks are limited to cache managed blocks.

Syntax

Parameters

FILE

The name of the database file to verify,

START

The starting block address to verify. Specify block addresses in Oracle blocks (as opposed to operating system blocks). If you do not specify START, DB_VERIFY defaults to the first block in the file.

END

The ending block address to verify. If you do not specify END, DB_VERIFY defaults to the last block in the file.

BLOCKSIZE

BLOCKSIZE is required only if the file to be verified has a non-2kb block size. If you do not specify BLOCKSIZE for non-2kb files, you will see the error DBV-00103.

LOGFILE

Specifies the file to which logging information should be written. The default sends output to the terminal display.

FEEDBACK

Specifying the keyword FEEDBACK causes DB_VERIFY to send a progress display to the terminal in the form of a single dot "." for n number of pages verified during the DB_VERIFY run. If
n = 0, there will be no progress display.

HELP

Provides onscreen help.

PARFILE

Specifies the name of the parameter file to use. You can store various values for DB_VERIFY parameters in flat files allowing you to have parameter files customized for specific types of integrity checks and/or for different types of datafiles.

Enterprise Manager

Enterprise Manager can be used to perform the verification process as well. The verification of the entire database or a tablespace will be managed by Enterprise Manager in that it will invoke the verification process on each individual file.

For more information, see your Enterprise Manager documentation.

Sample DB_VERIFY Output

The following example shows how to get online help:

% dbv help=y 
 
DBVERIFY: Release 7.3.1.0.0 - Wed Aug  2 09:14:36 1995 
 
Copyright (c) Oracle Corporation 1979, 1994.  All rights reserved. 
 
Keyword   Description        (Default) 
---------------------------------------------- 
FILE      File to Verify     (NONE) 
START     Start Block        (First Block of File) 
END       End Block          (Last Block of File) 
BLOCKSIZE Logical Block Size (2048)
LOGFILE   Output Log         (NONE)

This is sample output of verification for the file, t_db1.f. The feedback parameter has been given the value 100 to display one dot onscreen for every 100 pages processed:

% dbv file=t_db1.f feedback=100 
 
DBVERIFY: Release 7.3.1.0.0 - Wed Aug  2 09:15:04 1995 
 
Copyright (c) Oracle Corporation 1979, 1994.  All rights reserved. 
 
DBVERIFY - Verification starting : FILE = t_db1.f 

............................................................................
....
 

DBVERIFY - Verification complete 
 
Total Pages Examined         : 9216 
Total Pages Processed (Data) : 2044 
Total Pages Failing   (Data) : 0 
Total Pages Processed (Index): 733 
Total Pages Failing   (Index): 0 
Total Pages Empty            : 5686 
Total Pages Marked Corrupt   : 0 

Total Pages Influx           : 0