Using DBVERIFY to Validate Disk Blocks of a Single Data File

In this mode, DBVERIFY scans one or more disk blocks of a single data file and performs page checks.

Note:

If the file you are verifying is an Oracle Automatic Storage Management (Oracle ASM) file, then you must supply a USERID. This is because DBVERIFY needs to connect to an Oracle instance to access Oracle ASM files.

DBVERIFY Syntax When Validating Blocks of a Single File

The syntax for DBVERIFY when you want to validate disk blocks of a single data file is as follows:

Description of the illustration dbverify.eps

DBVERIFY Parameters When Validating Blocks of a Single File

Descriptions of the DBVERIFY parameters used to validate blocks of a single file are as follows:

Parameter	Description
`USERID`	Specifies your username and password. This parameter is only necessary when the files being verified are Oracle ASM files.
`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`, then DBVERIFY defaults to the first block in the file.
`END`	The ending block address to verify. If you do not specify `END`, then DBVERIFY defaults to the last block in the file.
`BLOCKSIZE`	`BLOCKSIZE` is required only if the file to be verified does not have a block size of 2 KB. If the file does not have block size of 2 KB and you do not specify `BLOCKSIZE`, then you will receive the error DBV-00103.
`HIGH_SCN`	When a value is specified for `HIGH_SCN`, DBVERIFY writes diagnostic messages for each block whose block-level SCN exceeds the value specified. This parameter is optional. There is no default.
`LOGFILE`	Specifies the file to which logging information should be written. The default sends output to the terminal display.
`FEEDBACK`	Causes DBVERIFY to send a progress display to the terminal in the form of a single period (.) for `n` number of pages verified during the DBVERIFY run. If `n` = 0, then there is no progress display.
`HELP`	Provides online help.
`PARFILE`	Specifies the name of the parameter file to use. You can store various values for DBVERIFY parameters in flat files. This enables you to customize parameter files to handle different types of data files and to perform specific types of integrity checks on data files.

Sample DBVERIFY Output For a Single Data File

The following is a sample verification of the file t_db1.dbf.The feedback parameter has been given the value 100 to display one period (.) for every 100 pages processed. A portion of the resulting output is also shown.

% dbv FILE=t_db1.dbf FEEDBACK=100
.
.
.
DBVERIFY - Verification starting : FILE = t_db1.dbf 

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

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

Notes:

Pages = Blocks
Total Pages Examined = number of blocks in the file
Total Pages Processed = number of blocks that were verified (formatted blocks)
Total Pages Failing (Data) = number of blocks that failed the data block checking routine
Total Pages Failing (Index) = number of blocks that failed the index block checking routine
Total Pages Marked Corrupt = number of blocks for which the cache header is invalid, thereby making it impossible for DBVERIFY to identify the block type
Total Pages Influx = number of blocks that are being read and written to at the same time. If the database is open when DBVERIFY is run, then DBVERIFY reads blocks multiple times to get a consistent image. But because the database is open, there may be blocks that are being read and written to at the same time (INFLUX). DBVERIFY cannot get a consistent image of pages that are in flux.