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Re: ROLLBACK SEGMENT?

From: <Rajesh.Rao_at_chase.com>
Date: Thu, 24 Jan 2002 14:37:12 -0800
Message-ID: <F001.003FA993.20020124142519@fatcity.com>

>> Export doesn't generate any rollback, right, so what is it supposed to
>> accomplish by doing this incantation?

>Sorry to press the point, but could you elaborate on how that "COULD"
>possibly make any difference for 'snapshot too old'?

For the same reason, any other transaction could end up with a snapshot too old error. Export does not generate any rollback, but there could be users performing DML operations on the table that is being exported, and the export needs to be redirected to read from the rollback segments. The likelihood of the error being thrown up especially if one uses the consistent parameter could be very high, if you dont have a large enough rollback segment without an optimal clause.

Raj

Jeremiah Wilton <jwilton_at_speakeasy.net>@fatcity.com on 01/23/2002 11:20:40 AM

Please respond to ORACLE-L_at_fatcity.com

Sent by: root_at_fatcity.com

To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com> cc:

On Tue, 22 Jan 2002, Rajesh.Rao_at_chase.com wrote:

> Hmmmm ... "COULD" help in avoiding snapshot too old errors.

Sorry to press the point, but could you elaborate on how that "COULD" possibly make any difference for 'snapshot too old'?

--
Jeremiah Wilton
http://www.speakeasy.net/~jwilton


> Jeremiah Wilton <jwilton_at_speakeasy.net> wrote:
>
> So what does it accomplish to "assign export [to] a particular
> rollback segment?"
>
> Export doesn't generate any rollback, right, so what is it supposed to
> accomplish by doing this incantation?
>
> On Tue, 22 Jan 2002, Jason Rowski wrote:
>
> > ... you can use the following trick to assign export a
> > particular rollback segment -
> >
> > 1) Create a rollback segment tablespace with one large
> > segment and bring it online before export.
> > 2) Offline all existing rollback segments.
> > 3) Export the database
> > 4) Offline the large tablespace created earlier.
> > 5) Bring back the orginals rollback segments online.
> >
> >
> > --- Seema Singh <oracledbam_at_hotmail.com> wrote:
> > > Can I use one rollback segment at time of export?Is
> > > yes,then
> > > SET TRANSACTION USE ROLLBACK SEGMENT
> > > rollbacksegmentname;
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jeremiah Wilton INET: jwilton_at_speakeasy.net Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: INET: Rajesh.Rao_at_chase.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
Received on Thu Jan 24 2002 - 16:37:12 CST

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