All Oracle Error Codes
Oracle DBA Forum

Frequent Oracle Errors

TNS:could not resolve the connect identifier specified
Backtrace message unwound by exceptions
invalid identifier
PL/SQL compilation error
internal error
missing expression
table or view does not exist
end-of-file on communication channel
TNS:listener unknown in connect descriptor
insufficient privileges
PL/SQL: numeric or value error string
TNS:protocol adapter error
ORACLE not available
target host or object does not exist
invalid number
unable to allocate string bytes of shared memory
resource busy and acquire with NOWAIT specified
error occurred at recursive SQL level string
ORACLE initialization or shutdown in progress
archiver error. Connect internal only, until freed
snapshot too old
unable to extend temp segment by string in tablespace
Credential retrieval failed
missing or invalid option
invalid username/password; logon denied
unable to create INITIAL extent for segment
out of process memory when trying to allocate string bytes
shared memory realm does not exist
cannot insert NULL
TNS:unable to connect to destination
remote database not found ora-02019
exception encountered: core dump
inconsistent datatypes
no data found
TNS:operation timed out
PL/SQL: could not find program
existing state of packages has been discarded
maximum number of processes exceeded
error signaled in parallel query server
ORACLE instance terminated. Disconnection forced
TNS:packet writer failure
see ORA-12699
missing right parenthesis
name is already used by an existing object
cannot identify/lock data file
invalid file operation
quoted string not properly terminated

RE: Identifying the content of a corrupted block in system tablespace

Vlado Barun


Thanks for the queries however they returned no rows, which I accutally
expected, since obj$ is not part of the c_obj# cluster, which is the cluster
that has the corrupted block (see my original post). So, I didn't even need
to use the alter session...

BTW, in the second and third query you need to adjust the index name...

So, what I did is to loop through each object in obj$ and try to access the
data. See code below. In this way I identified 3 tables, 2 views and a
synonym that are affected by the corrupted block. Fortunately, the three
tables are not needed anymore, and I should be able to rebuild the 2 views
and synonym.

So, my next question is what are my options in regards to resolving this

Currently, I see the following options:
1) As somebody mentioned before, if the row data and not the block header
data is corrupt, then by just dropping the objects, the corruption might go
2) Create an empty database, export objects from corrupted database and
import all the objects into the new database.

I like option 1, but if it doesn't work is there any other less resource
intensive way to resolve this than option 2?

create or replace procedure access_all_data
l_sql_string varchar2(2000);
l_type  number;
l_object_name varchar2(30);
l_owner    varchar2(30);
l_cursor_name INTEGER;
l_ignore integer;
l_sqlerrm varchar2(4000);
l_row_count number;
cursor objs is
 select o.name object_name
     , o.type# type
     , u.name owner
 from sys.obj$ o
    , sys.user$ u
 where o.owner# = u.user#
 and u.name not in ('SYSTEM', 'SYS')
--  and rownum <11
 ORDER BY u.name, o.name;
 for obj_rec in objs loop
     l_object_name:= obj_rec.object_name;
     l_owner:= obj_rec.owner;
     l_type:= obj_rec.type;
     l_sql_string:='select /*+ full(t) noparallel(t) */
count(*) from ' || l_owner || '.' || l_object_name || ' T';
      l_cursor_name := dbms_sql.open_cursor;
             , l_sql_string
           , SYS.DBMS_SQL.native);
     DBMS_SQL.DEFINE_COLUMN(l_cursor_name, 1,
      l_ignore := dbms_sql.execute(l_cursor_name);
     l_ignore := DBMS_SQL.FETCH_ROWS(l_cursor_name);
     DBMS_SQL.COLUMN_VALUE(l_cursor_name, 1,
     insert into object_avail(owner, object_name, type,
     values (l_owner, l_object_name, l_type,
      when others then
      l_sqlerrm := sqlerrm;
      insert into object_avail(owner, object_name, type,
      values (l_owner, l_object_name, l_type, l_sqlerrm);
 end loop;

Vlado Barun, M.Sc.
Mobile: 865 335 7652
AIM: vbarun2

-----Original Message-----
From: Parker, Matthew [mailto:matthewp@(protected)]
Sent: Friday, January 07, 2005 10:56 AM
To: vlado@(protected)
Subject: RE: Identifying the content of a corrupted block in system

Here are the three queries (Jeremiah was referring to, (nice to know your
still having fun jeremiah although your company name is kind of funny)) in
order to return the most data available, easily:

--So the the second part of the minus will bypass the bad block.

select /*+ INDEX (o I_OBJ_1) */ obj# from obj$ o
select /*+ FULL (o) */ obj# from obj$ o;

select /*+ INDEX (o I_OBJ_1) */
owner#,name,namespace,remoteowner,linkname,subname from obj$ o
select /*+ FULL (o) */ owner#,name,namespace,remoteowner,linkname,subname
from obj$ o;

select /*+ INDEX (o I_OBJ_1) */ oid$ from obj$ o
select /*+ FULL (o) */ oid$ from obj$ o;

To fix this becomes more complex:
1. Does your friend have any backups of the database? How old are the
backups? Is there a continuous redo chain for the backup?

2. Actual repair of the block would require at least a trace dump and a
block dump.
alter system dump datafile '/u100/oradata/fstst/system01.dbf' block 8002;
(You will need to fill in the appropriate database blocksize for the bs=
paramter in bytes)
dd if=/u100/oradata/fstst/system01.dbf of=dd_df_1_bl_8002_curr.dd bs=8192
skip=8002 count=1 conv=notrunc

Once this information is available then some choices can be made to fix the

-----Original Message-----
From: oracle-l-bounce@(protected)]
On Behalf Of Vlado Barun
Sent: Thursday, January 06, 2005 6:24 PM
To: oracle-l@(protected)
Subject: Identifying the content of a corrupted block in system tablespace

I have a corrupted block in the system tablespace.
I used the standard query to identify the object that the block but it

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: ORACLE data block corrupted (file # 1, block # 8002)
ORA-01110: data file 1: '/u100/oradata/fstst/system01.dbf'

Then I did this:

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

----- ------------ ------------ ---------------- -------- ------
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