Re: FW: My worst nightmare - ORA-8103
- From: Maureen English <maureen.english@xxxxxxxxxx>
- To: gerwin.hendriksen@xxxxxxxxx, mwf@xxxxxxxx
- Date: Wed, 11 Jun 2014 20:09:45 -0800
Thanks! I updated our ticket with Oracle asking for info on this bug. I can't
find anything about it on Metalink.
Regarding Mark's post, does this mean that the reason users aren't seeing any
problems is because
they are able to access the data because the application uses the indexes when
querying?
We did have to create a new undo tablespace due to corruption in the undo
tablespace.
At least one of the indexes got an ORA-8103 when running analyze on it. I
didn't check the others.
Now I'm starting to panic again. Oracle says that the data is lost, but now it
might not be???
Interestingly enough, we were able to fix the other issues that we've found by
recreating indexes, or stepping through
a table using a value from a unique index and then find the corrupt or
duplicate rows and delete them. This table
doesn't have a unique index...and it has 553M+ rows. It takes 20 minutes just
to get a rowcount back :-(
I ended up following Oracle's suggestion of copying the rows that didn't return
the ORA-8102 error to another table,
exported that table, truncated my application table, dropped the indexes on the
application table and imported the
data back in. I'm currently rebuilding the indexes. Tomorrow will be when the
2 main Finance users will check things
out and let me know the status.
I'm so dreading the possibility of someone telling me that all of a sudden
nothing balances...especially when it all
seems to be in balance now....
- Maureen
On 6/11/2014 5:59 AM, Gerwin Hendriksen wrote:
Hello Maureen,
The ORA-8103 can occur when the block contains a vector to an undo segment and
for some reason the change can't be found
in the undo segment. Years ago I logged a bug at Oracle (at that time working
for Oracle Support) describing a situation
when recovering a database ending in an ORA-8103 or ORA-600 [4146], when
selecting a table. Because the issue described
here is in a reporting database, this bug although a very old bug could be
underneath. The bug is caused by the way redo
is applied and a small issue there might give the same situation as described
in the bug. The bug was filed 31 march
2001 and has number 1714688, the bug is probably never really fixed because
fixing it would mean a major design change
in the redo apply. Further more the bug was encountered due to human error in
the way the recovery was done. Just ask
support that this bug might give an idea why you encounter the ORA-8103.
Good luck and kind regards,
Gerwin Hendriksen
2014-06-11 14:01 GMT+02:00 Mark W. Farnham <mwf@xxxxxxxx <mailto:mwf@xxxxxxxx>>:
Sorry, missed the list.
-----Original Message-----
From: Mark W. Farnham [mailto:mwf@xxxxxxxx <mailto:mwf@xxxxxxxx>]
Sent: Tuesday, June 10, 2014 2:43 PM
To: 'maureen.english@xxxxxxxxxx <mailto:maureen.english@xxxxxxxxxx>'
Subject: RE: My worst nightmare - ORA-8103
If a unique index survives, you should be able to retrieve the rowids for
the rows not in your recovery target table with a minus.
Then, using the rowids and column sets for indexes, you can retrieve at
least those column values from the indexes.
This at least should provide you with a complete set of keys for the missing
rows.
I presume you lack the ability to do individual block patching via RMAN,
etc.
good luck,
mwf
-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx <mailto:oracle-l-bounce@xxxxxxxxxxxxx>
[mailto:oracle-l-bounce@xxxxxxxxxxxxx
<mailto:oracle-l-bounce@xxxxxxxxxxxxx>]
On Behalf Of Maureen English
Sent: Tuesday, June 10, 2014 2:29 PM
To: oracle-l@xxxxxxxxxxxxx <mailto:oracle-l@xxxxxxxxxxxxx>
Subject: My worst nightmare - ORA-8103
Hi,
Original post to BOracle list...apologies to those who are seeing this
again.
On 5/31, the refresh of a materialized view in our reporting instance failed
with an ORA-8103 error, as did a gather stats job for the same table in the
production database. We had an application upgrade done on 6/1 and copied
our production database to a preprod version on 6/2, so the errors weren't
caught immediately.
Users complained that the current data wasn't available in the reporting
instance but my attempts to refresh and recreate all failed with the same
ORA-8103 error.
I've been working with Oracle Support since early last week and keep hitting
brick walls. At the moment, we've managed to copy 'uncorrupted' rows out of
the table in our preproduction database and are 480 rows short in a table
with 550M rows in it. Oracle is currently working to identify the rowids of
the corrupt blocks based on the output in a trace file generated by a
failing query.
I'm looking at Document 336133.1 while I wait for more info from Oracle.
Anyone have any comments/suggestions/other info that might help identify and
fix the problem? We really can't afford to lose that much data. We're
working on recovering our database to a different location to try to get
back any data that we lose, but since I don't have any idea what caused the
corruption, I'm lost.
- Maureen
--
//www.freelists.org/webpage/oracle-l
--
//www.freelists.org/webpage/oracle-l
--
Maureen English
Lead Database Administrator
University of Alaska
Fairbanks, AK
(907) 450-8329
--
//www.freelists.org/webpage/oracle-l
Other related posts:
