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