DB_VERIFY (dbv) is a utility than can be used to perform a physical structure integrity check against off-line database files.
This utility runs perfectly well against on-line files as well, however, the manual is clear that it is an off-line utility. My assumption is that it may incorrectly report blocks as bad while I/O is taken place (fractured blocks).
DBA's should use this utility frequently to identify datafiles that are corrupted. Some times the database will perform normally until you address a particular block in the datafile, which may then result in ORA-600 errors.
DB_VERIFY is useful in these situations:
- When block corruption is expected;
- Forecast any future problems w.r.t. database file/ block corruption;
- When you restore files from a tape. It will help knowing if the first file pulled from tape is corrupt, instead of spending hours to extract all of them.
To access help on DB_VERIFY type:
$ dbv file=/u01/oradata/o10gr2/example01.dbf DBVERIFY: Release 10.2.0.1.0 - Production on Sat Jul 7 11:45:52 2007 Copyright (c) 1982, 2005, Oracle. All rights reserved. DBVERIFY - Verification starting : FILE = /u01/oradata/o10gr2/example01.dbf DBVERIFY - Verification complete Total Pages Examined : 12800 Total Pages Processed (Data) : 4409 Total Pages Failing (Data) : 0 Total Pages Processed (Index): 1264 Total Pages Failing (Index): 0 Total Pages Processed (Other): 1539 Total Pages Processed (Seg) : 0 Total Pages Failing (Seg) : 0 Total Pages Empty : 5588 Total Pages Marked Corrupt : 0 Total Pages Influx : 0 Highest block SCN : 470536 (0.470536)