Re: corrupted block

We had a session with an expert on Monday and he recommended export to \dev\nul to detect errors in the database.

Yechiel Adar
Mehish
----- Original Message -----
To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com> Sent: Monday, February 24, 2003 10:41 PM

> I had the same belief that RMAN catches the corruption earlier, but not
NOW.
>
> We had a database crash two months back and while performing the
> recovery(RMAN) one of the restored data file was corrupted. *BIG SHOCK*
to
> everyone..We ran the dbverify on the restored files, the corruption showed
> up easily.. But not a single clue on the RMAN backup logs'.
>
> We asked Oracle Support, if rman checks for corruption in the data files
> when the data files are being backed up.. He said "No"..
>
> Oracle Ver: 8.1.7.2/Sun 2.6
>
>
> ..Ponnusamy
>
> At 11:40 AM 2/24/2003 -0800, DENNIS WILLIAMS wrote:
> >Stephen
> > RMAN ignored your corrupted block? Ya gotta tell us more man! We're
> >relying on it to catch everything. Did you have the MAXCORRUPT parameter
> >set?
> >
> >Dennis Williams
> >DBA, 40%OCP, 100% DBA
> >Lifetouch, Inc.
> >dwilliams_at_lifetouch.com
> >
> >
> >-----Original Message-----
> >Sent: Monday, February 24, 2003 11:45 AM
> >To: Multiple recipients of list ORACLE-L
> >
> >
> >
> >I think more recent versions of Oracle have options for skipping corrupt
> >blocks with exports.
> >
> >One possible way:
> >If you have a valid primary key index on the table, and the index is in a
> >good tablespace, you might be able to cycle through all the primary keys,
> >select the row corresponding to that primary key and insert it into a new
> >table. I was able to do this about a month ago with a 8.1.7 database.
In
> >my case, I think it was a block header that was corrupt, not data; so I
got
> >all the data OK. It was rather slow, grabbing and inserting one row at a
> >time; but I got all the data. As long as I didn't do anything that would
> >cause a table scan of any kind, I could get the data.
> >
> >By the way, rman not only failed to spot the corruption, but backed it up
> >AND restored the corruption! My initial attempt was to just rename the
> >datafile at the file system level, then recover it from the previous
backup.
> >I could relate another one of those TAR non-support -- total and complete
> >NON-support! -- on this one.
> >
> > > -----Original Message-----
> > >
> > > So my question is, if all backups contain the corrupted
> > > block, how would
> > > I copy all non-corrupted blocks from this table into a new table?
> > >
> >--
> >Please see the official ORACLE-L FAQ: http://www.orafaq.net
> >--
> >Author: Stephen Lee
> > INET: Stephen.Lee_at_DTAG.Com
> >
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> >Author: DENNIS WILLIAMS
> > INET: DWILLIAMS_at_LIFETOUCH.COM
> >
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> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: Ponnusamy
> INET: t_pranga_at_qualcomm.com
>
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-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Yechiel Adar
  INET: adar76_at_inter.net.il

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