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Re: Rollback segment question

From: Tony Adolph <tony.adolph_at_viaginterkom.de>
Date: Tue, 12 Oct 1999 23:05:43 GMT
Message-ID: <7u0erv$iio$1@nnrp1.deja.com>

> > You have missed using the following comand before you run the
query/report:
> >
> > SQL> alter session set transaction read only; -- this will mark the
select
> > has a transaction
> > SQL> ... long running query ...
> > SQL> commit; -- This will free out the space reserved in the
rollback space
>
> That will not prevent ORA-1555. The ability to obtain a consistent
read of a
> data block depends on rebuilding a block the way it looked when a
query
> started, based on rollback entries throughout many different rollback
segments,
> from other, already committed and gone transactions that were
performed in
> other sessions since the user's query was started. It has nothing to
do with
> declaring a rollback segment for the session doing the query.
>
> Setting a transaction READ ONLY actually sets the base SCN to which
all reads
> must be consistent, increasing the likelihood of ORA-1555.
>
> --

Hi Jeremiah,

So whats the best way to avoid the problem?

Tony

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Before you buy. Received on Tue Oct 12 1999 - 18:05:43 CDT

Original text of this message

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