Problem solved. Because it's a datafile for the TEMP tablespace and apparently this file hasn't been used since instance startup about 19 hours ago, I could shrink the file from 102760448 to 1k in SQL*Plus (actually to 24576 bytes as viewed by OS, probably because of datafile header overhead). Ran dbv again with no corruption. Resized the file back to 102760448 in SQL*Plus. Confirmed with dbv; no corruption. The following OS screen and SQL*Plus screen should be interleaved: DBVERIFY: Release 7.3.4.4.0 - Production on Wed Sep 5 01:01:52 2001 Copyright (c) Oracle Corporation 1979, 1996. All rights reserved. DBVERIFY - Verification starting : FILE = /db012/oracle/oradata/prma/tempPRMA0.d bf Page 292 is marked software corrupt DBVERIFY - Verification complete Total Pages Examined : 12544 Total Pages Processed (Data) : 0 Total Pages Failing (Data) : 0 Total Pages Processed (Index): 0 Total Pages Failing (Index): 0 Total Pages Empty : 5403 Total Pages Marked Corrupt : 1 Total Pages Influx : 0 oracle AT hera:prma:/oracle/home>ls -l /db012/oracle/oradata/prma/tempPRMA0.dbf -rw-rw---- 1 oracle dba 24576 Sep 5 09:08 /db012/oracle/oradata/prma /tempPRMA0.dbf oracle AT hera:prma:/oracle/home>dbv /db012/oracle/oradata/prma/tempPRMA0.dbf bl> DBVERIFY: Release 7.3.4.4.0 - Production on Wed Sep 5 09:09:22 2001 Copyright (c) Oracle Corporation 1979, 1996. All rights reserved. DBVERIFY - Verification starting : FILE = /db012/oracle/oradata/prma/tempPRMA0.d bf DBVERIFY - Verification complete Total Pages Examined : 2 Total Pages Processed (Data) : 0 Total Pages Failing (Data) : 0 Total Pages Processed (Index): 0 Total Pages Failing (Index): 0 Total Pages Empty : 0 Total Pages Marked Corrupt : 0 Total Pages Influx : 0 oracle AT hera:prma:/oracle/home>dbv /db012/oracle/oradata/prma/tempPRMA0.dbf bl> DBVERIFY: Release 7.3.4.4.0 - Production on Wed Sep 5 09:11:24 2001 Copyright (c) Oracle Corporation 1979, 1996. All rights reserved. DBVERIFY - Verification starting : FILE = /db012/oracle/oradata/prma/tempPRMA0.d bf DBVERIFY - Verification complete Total Pages Examined : 12544 Total Pages Processed (Data) : 0 Total Pages Failing (Data) : 0 Total Pages Processed (Index): 0 Total Pages Failing (Index): 0 Total Pages Empty : 12542 Total Pages Marked Corrupt : 0 Total Pages Influx : 0 SQL> select * from dba_data_files where file_name = '/db012/oracle/oradata/prma/tempPRMA0.dbf'; FILE_NAME ----------------------------------------------------------------------------------------------------- FILE_ID TABLESPACE_NAME BYTES BLOCKS STATUS ---------- ------------------------------ ---------- ---------- --------- /db012/oracle/oradata/prma/tempPRMA0.dbf 4 TEMP 102760448 12544 AVAILABLE SQL> select * from dba_extents where file_id = 4 and 292 between block_id and (block_id + blocks -1); no rows selected SQL> select * from dba_segments where header_file = 4; no rows selected SQL> alter database datafile '/db012/oracle/oradata/prma/tempPRMA0.dbf' resize 1k; Database altered. SQL> alter database datafile '/db012/oracle/oradata/prma/tempPRMA0.dbf' resize 102760448; Database altered. SQL> select * from v$instance; KEY VALUE ---------------------------------------------------------------- ---------- RESTRICTED MODE 0 SHUTDOWN PENDING 0 STARTUP TIME - JULIAN 2452154 STARTUP TIME - SECONDS 68739