Re: rollback question

Norbert Ferstl <ferstl_at_netway.at> wrote in article <343D12C7.E58EF2A0_at_netway.at>...
> Chuck Hamilton wrote:
> >
> > Someone recently told me that all rollback extents for a transaction
 must
> > be contiguous. If a transaction attempts to allocate the next RBS
 extent,
> > and that extent was already assigned to another transaction, that the
 first
> > transaction will fail with a "snapshot too old" error. It will not skip
> > over that extent and grab the next one. Is this true?
> > --
> > Chuck Hamilton
> > Xchuckh_at_dvol.com
> >
> > In an effort to reduce spam, my return address has been altered.
> > To reply, remove the X from the address.
>
>
> You are wrong
>
> 1. extents must not be contiguos but every extent can only hold
> one transaction at one time

you are wrong.

Here is the quote from Oracle DBA Handbook 7.3 edition page 214

"each block within that [rollback] extent must contain information for only one transaction. Blocks from different transactions can be stored in the same extent."

Cordially,
Serge

> 2. snapshot too old occurs if a consistent read cannot get
> consistent data previous to a commited transaction, that has
> not been commited at the start of the consistent read.
>
>
> =====================================
> Norbert Ferstl
> DI Forsthuber GmbH
> Kohlbauernstr. 17
> A-2630 Ternitz, AUSTRIA
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> Fax: +43 2630 3825014
> <ferstl_at_netway.at>
> =====================================
>
Received on Thu Oct 09 1997 - 00:00:00 CDT