Re: Block Corruption in empty pages in Oracle 11g
From: zigzagdna <zigzagdna_at_yahoo.com>
Date: Thu, 5 Aug 2010 09:59:52 -0700 (PDT)
Message-ID: <b8974c69-40e2-4ff1-93b3-0682a81de9b5_at_5g2000yqz.googlegroups.com>
On Aug 5, 8:18 am, Mark D Powell <Mark.Powe..._at_hp.com> wrote:
> On Aug 4, 11:08 pm, zigzagdna <zigzag..._at_yahoo.com> wrote:
>
>
>
>
>
> > I am using Oracle 11.1.0.7.1 on HP UNIX 11i.
> > On several occasions, I have been seen that block corruptions are
> > reported by rman. I have never seen this problem in previous release
> > of databases; but I have seen it more than once in Oracle 11g.
> > However, when I run dbv command; I do not see any corruption in data
> > and index blocks; so my conclusion is block corruption is in empty
> > pages.
> > Anyone has ideas why block corruption occurs in Oracle 11g. Has
> > Oracle’s algorithm for checking block corruption have changed in 11g;
> > I.e.; these corruptions existed in older Oracle releases but not
> > reported by rman,
>
> > Another strange thing I noticed:
> > 1. When doing export backup, export backup reports about corrupted
> > blocks.
> > 2. When I do expdp no errors are reported.
> > So question is why is exp command checking empty blocks?
>
> > Any insights in above will be appreciated.
>
> If the rman backup and expdp are identifying corrupted blocks what
> does the following query show?
>
> set echo off
> --
> -- Display corrupt block information
> --
> -- 20100105 Mark D Powell Save 4 future use
> --
> select
> *
> from
> v$database_block_corruption
> order by
> file#
> ,block#
> /
>
> You can find the object idenfified by this query by looking at
> dba_extents for the extent that the identified files and blocks are
> held within.
>
> HTH -- Mark D Powell --- Hide quoted text -
>
> - Show quoted text -
Date: Thu, 5 Aug 2010 09:59:52 -0700 (PDT)
Message-ID: <b8974c69-40e2-4ff1-93b3-0682a81de9b5_at_5g2000yqz.googlegroups.com>
On Aug 5, 8:18 am, Mark D Powell <Mark.Powe..._at_hp.com> wrote:
> On Aug 4, 11:08 pm, zigzagdna <zigzag..._at_yahoo.com> wrote:
>
>
>
>
>
> > I am using Oracle 11.1.0.7.1 on HP UNIX 11i.
> > On several occasions, I have been seen that block corruptions are
> > reported by rman. I have never seen this problem in previous release
> > of databases; but I have seen it more than once in Oracle 11g.
> > However, when I run dbv command; I do not see any corruption in data
> > and index blocks; so my conclusion is block corruption is in empty
> > pages.
> > Anyone has ideas why block corruption occurs in Oracle 11g. Has
> > Oracle’s algorithm for checking block corruption have changed in 11g;
> > I.e.; these corruptions existed in older Oracle releases but not
> > reported by rman,
>
> > Another strange thing I noticed:
> > 1. When doing export backup, export backup reports about corrupted
> > blocks.
> > 2. When I do expdp no errors are reported.
> > So question is why is exp command checking empty blocks?
>
> > Any insights in above will be appreciated.
>
> If the rman backup and expdp are identifying corrupted blocks what
> does the following query show?
>
> set echo off
> --
> -- Display corrupt block information
> --
> -- 20100105 Mark D Powell Save 4 future use
> --
> select
> *
> from
> v$database_block_corruption
> order by
> file#
> ,block#
> /
>
> You can find the object idenfified by this query by looking at
> dba_extents for the extent that the identified files and blocks are
> held within.
>
> HTH -- Mark D Powell --- Hide quoted text -
>
> - Show quoted text -
Yes, tis query shows some block corruptions but it does not tell you corrupted blocks are empty. When I run dbv it does not show any corruption in data or indexes. So I am assuming that corruption is in empty pages. Received on Thu Aug 05 2010 - 11:59:52 CDT