Identifying the content of a corrupted block in system tablespace 2005-01-06 - By Vlado Barun
I have a corrupted block in the system tablespace.
I used the standard query to identify the object that the block but it
failed:
SQL>
1 SELECT segment_name
2 , segment_type
3 , owner
4 , tablespace_name
5 , block_id
6 , blocks
7 FROM sys.dba_extents
8 WHERE file_id = 1
9* AND 8002 BETWEEN block_id and block_id + blocks -1 FROM sys.dba_extents
*
ERROR at line 7:
ORA-01578 (See ORA-01578.ora-code.com): ORACLE data block corrupted (file # 1, block # 8002)
ORA-01110 (See ORA-01110.ora-code.com): data file 1: '/u100/oradata/fstst/system01.dbf'
Then I did this:
ALTER SESSION SET EVENTS '10231 TRACE NAME CONTEXT FOREVER, LEVEL 10';
select owner
, segment_name
, segment_type
, tablespace_name
, block_id
, blocks
from dba_extents
where file_id=1
and block_id in (
select max(block_id)
from dba_extents
where file_id=1
and block_id <= 8002
);
OWNER SEGMENT_NAME SEGMENT_TYPE TABLESPACE_NAME BLOCK_ID BLOCKS
-- -- -- ---- ---- -- ---- ---- -- ---- ---- --- -- ----- -- ---
SYS C_OBJ# CLUSTER SYSTEM 7978 25
So, the object that the corrupt block belongs to is c_obj#.
Is that correct?
If so, and since c_obj# stores data about objects (metadata), it basically
means that I can not access the object whose metadata is in that block.
So, I'm trying to identify which object is lost.
For example, if it's just an index, I should be able to export all the
objects from database into a new database and rebuild the index, and resolve
the corruption in that way. Any idea how I can identify the object whose
metadata is lost?
I'm aware that Oracle support should be contacted, however a friend of mine
asked me to look into this before they contact Oracle Support since they
don't have a support contract anymore...
BTW, this is 8.0.6, they identified this problem 3 months ago in their
Peoplesoft application, and of course they don't have a good backup from
which to recover...
Vlado Barun, M.Sc.
Mobile: 865 335 7652
AIM: vbarun2
--
http://www.freelists.org/webpage/oracle-l
|
|
