RE: A rollback segment question on minextents

2002-03-20 Thread kumanan . balasundaram

OK, 

Thanks to all of you for the input.
Only if we can can have a big storage to put all the Oracle internals into
our brains :)

There is a nice article in Metalink : Note 62005.1

Cheers
Kumanan

> -Original Message-
> From: Rachel Carmichael [SMTP:[EMAIL PROTECTED]]
> Sent: 15 March 2002 20:59
> To:   Multiple recipients of list ORACLE-L
> Subject:  RE: A rollback segment question on minextents
> 
> yes, Jonathan Lewis was kind enough to correct me privately on this.
> 
> It is indeed only the first block that's used for header information,
> the rest of the block is used for rollback change vectors.
> 
> 
> --- [EMAIL PROTECTED] wrote:
> > While on the subject..
> > Please see the Oracle Metalink Note: 1029850.6.
> > It says the first "block" of the first segment contains header 
> > information.
> > 
> > 
> > > -Original Message-
> > > From: Kumanan Balasundaram 
> > > Sent:     15 March 2002 17:59
> > > To:   '[EMAIL PROTECTED]'
> > > Cc:   '[EMAIL PROTECTED]'
> > > Subject:  RE: A rollback segment question on minextents
> > > 
> > > Oracle recommends the size NEXT=INITIAL.
> > > So if I had 10M initial, then most of the initial beyond the 
> > > header info will be wasted? Sure not!
> > > 
> > > Kumanan
> > > 
> > >   -Original Message-
> > >   From:   Rachel Carmichael [SMTP:[EMAIL PROTECTED]]
> > >   Sent:   11 March 2002 21:48
> > >   To: Multiple recipients of list ORACLE-L
> > >   Subject:RE: A rollback segment question on minextents
> > > 
> > >   the first extent is used by oracle as the segment header to manage
> > > the
> > >   transaction information within the rollback segment. The second
> > > extent
> > >   contains the actual change vectors
> > > 
> > > 
> > >   --- [EMAIL PROTECTED] wrote:
> > >   > Hi,
> > >   > 
> > >   > My point was that it could allocate one more extent as per need.
> > > Why
> > >   > the
> > >   > need to minextents = 2?
> > >   > 
> > >   > Thanks
> > >   > Kumanan
> > >   > 
> > >   > > -Original Message-
> > >   > > From:   Stephane Faroult [SMTP:[EMAIL PROTECTED]]
> > >   > > Sent:   07 March 2002 20:54
> > >   > > To: Multiple recipients of list ORACLE-L
> > >   > > Subject:Re: A rollback segment question on minextents
> > >   > > 
> > >   > > [EMAIL PROTECTED] wrote:
> > >   > > > 
> > >   > > > Hi,
> > >   > > > 
> > >   > > > I was wondering why Oracle force minextents for rollback
> > >   > > > segments to be two. Why can't we have minextents zero or
> > >   > > > no minextents clause at all.
> > >   > > > 
> > >   > > > We can surely set initial extent to be large enough
> > ourselves
> > >   > > > and next extent sized accordingly.
> > >   > > > 
> > >   > > > Can someone enlighten me on the reason/thought behind this?
> > >   > > > 
> > >   > > > Many thanks
> > >   > > > 
> > >   > > > Kumanan Balasundaram
> > >   > > > Database Administrator, IT
> > >   > > > QXL ricardo plc
> > >   > > > www.qxl.com
> > >   > > > P: +44 (0)208 962 7409
> > >   > > 
> > >   > > Oracle doesn't reuse an extent which contains active
> > > transactions.
> > >   > What
> > >   > > do you think would happen when you reach the end of your
> > initial
> > >   > extent
> > >   > > ? Exactly.
> > >   > > -- 
> > >   > > Regards,
> > >   > > 
> > >   > > Stephane Faroult
> > >   > > Oriole Ltd
> > >   > > -- 
> > >   > > Please see the official ORACLE-L FAQ: http://www.orafaq.com
> > >   > > -- 
> > >   > > Author: Stephane Faroult
> > >   > >   INET: [EMAIL PROTECTED]
> > >   > > 
> > >   > > Fat City Network Services-- (858) 538-5051  FAX: (858)
> > > 538-5051
> > >   > > San Diego, California-- Public Internet access /
> > Mailing
> > >   > Lists
>

RE: A rollback segment question on minextents

2002-03-15 Thread Rachel Carmichael

yes, Jonathan Lewis was kind enough to correct me privately on this.

It is indeed only the first block that's used for header information,
the rest of the block is used for rollback change vectors.


--- [EMAIL PROTECTED] wrote:
> While on the subject..
> Please see the Oracle Metalink Note: 1029850.6.
> It says the first "block" of the first segment contains header 
> information.
> 
> 
> > -Original Message-
> > From:   Kumanan Balasundaram 
> > Sent:   15 March 2002 17:59
> > To: '[EMAIL PROTECTED]'
> > Cc: '[EMAIL PROTECTED]'
> > Subject:RE: A rollback segment question on minextents
> > 
> > Oracle recommends the size NEXT=INITIAL.
> > So if I had 10M initial, then most of the initial beyond the 
> > header info will be wasted? Sure not!
> > 
> > Kumanan
> > 
> > -Original Message-
> > From:   Rachel Carmichael [SMTP:[EMAIL PROTECTED]]
> > Sent:   11 March 2002 21:48
> > To: Multiple recipients of list ORACLE-L
> > Subject:RE: A rollback segment question on minextents
> > 
> > the first extent is used by oracle as the segment header to manage
> > the
> > transaction information within the rollback segment. The second
> > extent
> > contains the actual change vectors
> > 
> > 
> > --- [EMAIL PROTECTED] wrote:
> > > Hi,
> > > 
> > > My point was that it could allocate one more extent as per need.
> > Why
> > > the
> > > need to minextents = 2?
> > > 
> >     > Thanks
> > > Kumanan
> > > 
> > > > -Original Message-
> > > > From:   Stephane Faroult [SMTP:[EMAIL PROTECTED]]
> > > > Sent:   07 March 2002 20:54
> > > > To: Multiple recipients of list ORACLE-L
> > > > Subject:Re: A rollback segment question on minextents
> > > > 
> > > > [EMAIL PROTECTED] wrote:
> > > > > 
> > > > > Hi,
> > > > > 
> > > > > I was wondering why Oracle force minextents for rollback
> > > > > segments to be two. Why can't we have minextents zero or
> > > > > no minextents clause at all.
> > > > > 
> > > > > We can surely set initial extent to be large enough
> ourselves
> > > > > and next extent sized accordingly.
> > > > > 
> > > > > Can someone enlighten me on the reason/thought behind this?
> > > > > 
> > > > > Many thanks
> > > > > 
> > > > > Kumanan Balasundaram
> > > > > Database Administrator, IT
> > > > > QXL ricardo plc
> > > > > www.qxl.com
> > > > > P: +44 (0)208 962 7409
> > > > 
> > > > Oracle doesn't reuse an extent which contains active
> > transactions.
> > > What
> > > > do you think would happen when you reach the end of your
> initial
> > > extent
> > > > ? Exactly.
> > > > -- 
> > > > Regards,
> > > > 
> > > > Stephane Faroult
> > > > Oriole Ltd
> > > > -- 
> > > > Please see the official ORACLE-L FAQ: http://www.orafaq.com
> > > > -- 
> > > > Author: Stephane Faroult
> > > >   INET: [EMAIL PROTECTED]
> > > > 
> > > > 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: [EMAIL PROTECTED] (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: 
> > >   INE

RE: A rollback segment question on minextents

2002-03-15 Thread Rachel Carmichael

you aren't wrong :)


--- "Freeman, Robert " <[EMAIL PROTECTED]> wrote:
> Actually the rollback segment header in the first extent exists in a
> single
> block, the rest of the first extent, as I understand it, is available
> for
> undo. Thus making INITIAL and NEXT the same should be of no
> consequence in
> this regard.
> 
> It is my understanding (and I'm sure I will be corrected if I'm
> wrong) the
> reason for a requirement of 2 extents is to allow the tail/wrap
> architecture
> that Oracle uses for rollback segments. 
> 
> RF
> 
> Robert G. Freeman - Oracle8i OCP
> Oracle DBA Technical Lead
> CSX Midtier Database Administration
> 
> The Cigarette Smoking Man: Anyone who can appease a man's conscience
> can
> take his freedom away from him.
> 
> 
> 
> -Original Message-
> Sent: Friday, March 15, 2002 12:54 PM
> To: Multiple recipients of list ORACLE-L
> 
> 
> Oracle recommends the size NEXT=INITIAL.
> So if I had 10M initial, then most of the initial beyond the 
> header info will be wasted? Sure not!
> 
> Kumanan
> 
> > -Original Message-
> > From:   Rachel Carmichael [SMTP:[EMAIL PROTECTED]]
> > Sent:   11 March 2002 21:48
> > To: Multiple recipients of list ORACLE-L
> > Subject:RE: A rollback segment question on minextents
> > 
> > the first extent is used by oracle as the segment header to manage
> the
> > transaction information within the rollback segment. The second
> extent
> > contains the actual change vectors
> > 
> > 
> > --- [EMAIL PROTECTED] wrote:
> > > Hi,
> > > 
> > > My point was that it could allocate one more extent as per need.
> Why
> > > the
> > > need to minextents = 2?
> > > 
> > > Thanks
> > > Kumanan
> > > 
> > > > -Original Message-
> > > > From:   Stephane Faroult [SMTP:[EMAIL PROTECTED]]
> > > > Sent:   07 March 2002 20:54
> > > > To: Multiple recipients of list ORACLE-L
> > > > Subject:Re: A rollback segment question on minextents
> > > > 
> > > > [EMAIL PROTECTED] wrote:
> > > > > 
> > > > > Hi,
> > > > > 
> > > > > I was wondering why Oracle force minextents for rollback
> > > > > segments to be two. Why can't we have minextents zero or
> > > > > no minextents clause at all.
> > > > > 
> > > > > We can surely set initial extent to be large enough ourselves
> > > > > and next extent sized accordingly.
> > > > > 
> > > > > Can someone enlighten me on the reason/thought behind this?
> > > > > 
> > > > > Many thanks
> > > > > 
> > > > > Kumanan Balasundaram
> > > > > Database Administrator, IT
> > > > > QXL ricardo plc
> > > > > www.qxl.com
> > > > > P: +44 (0)208 962 7409
> > > > 
> > > > Oracle doesn't reuse an extent which contains active
> transactions.
> > > What
> > > > do you think would happen when you reach the end of your
> initial
> > > extent
> > > > ? Exactly.
> > > > -- 
> > > > Regards,
> > > > 
> > > > Stephane Faroult
> > > > Oriole Ltd
> > > > -- 
> > > > Please see the official ORACLE-L FAQ: http://www.orafaq.com
> > > > -- 
> > > > Author: Stephane Faroult
> > > >   INET: [EMAIL PROTECTED]
> > > > 
> > > > 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: [EMAIL PROTECTED] (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: [EMAIL PROTECTED]
> > > 
> > > Fat City Network Services-- (858) 538-5051  FAX: (858)
&

RE: A rollback segment question on minextents

2002-03-15 Thread Jared . Still

Thanks for the info Robert.

Personally, I usually have more urgent matters to deal with that preclude
worrying about a possible 10meg wasted in a rollback segment.  ;)

Jared






"Freeman, Robert " <[EMAIL PROTECTED]>
Sent by: [EMAIL PROTECTED]
03/15/02 11:23 AM
Please respond to ORACLE-L

 
To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]>
cc: 
        Subject:    RE: A rollback segment question on minextents


Actually the rollback segment header in the first extent exists in a 
single
block, the rest of the first extent, as I understand it, is available for
undo. Thus making INITIAL and NEXT the same should be of no consequence in
this regard.

It is my understanding (and I'm sure I will be corrected if I'm wrong) the
reason for a requirement of 2 extents is to allow the tail/wrap 
architecture
that Oracle uses for rollback segments. 

RF

Robert G. Freeman - Oracle8i OCP
Oracle DBA Technical Lead
CSX Midtier Database Administration

The Cigarette Smoking Man: Anyone who can appease a man's conscience can
take his freedom away from him.



-Original Message-
Sent: Friday, March 15, 2002 12:54 PM
To: Multiple recipients of list ORACLE-L


Oracle recommends the size NEXT=INITIAL.
So if I had 10M initial, then most of the initial beyond the 
header info will be wasted? Sure not!

Kumanan

> -Original Message-
> From:  Rachel Carmichael [SMTP:[EMAIL PROTECTED]]
> Sent:  11 March 2002 21:48
> To:Multiple recipients of list ORACLE-L
> Subject:   RE: A rollback segment question on minextents
> 
> the first extent is used by oracle as the segment header to manage the
> transaction information within the rollback segment. The second extent
> contains the actual change vectors
> 
> 
> --- [EMAIL PROTECTED] wrote:
> > Hi,
> > 
> > My point was that it could allocate one more extent as per need. Why
> > the
> > need to minextents = 2?
> > 
> > Thanks
> > Kumanan
> > 
> > > -Original Message-
> > > From:  Stephane Faroult [SMTP:[EMAIL PROTECTED]]
> > > Sent:      07 March 2002 20:54
> > > To:Multiple recipients of list ORACLE-L
> > > Subject:   Re: A rollback segment question on minextents
> > > 
> > > [EMAIL PROTECTED] wrote:
> > > > 
> > > > Hi,
> > > > 
> > > > I was wondering why Oracle force minextents for rollback
> > > > segments to be two. Why can't we have minextents zero or
> > > > no minextents clause at all.
> > > > 
> > > > We can surely set initial extent to be large enough ourselves
> > > > and next extent sized accordingly.
> > > > 
> > > > Can someone enlighten me on the reason/thought behind this?
> > > > 
> > > > Many thanks
> > > > 
> > > > Kumanan Balasundaram
> > > > Database Administrator, IT
> > > > QXL ricardo plc
> > > > www.qxl.com
> > > > P: +44 (0)208 962 7409
> > > 
> > > Oracle doesn't reuse an extent which contains active transactions.
> > What
> > > do you think would happen when you reach the end of your initial
> > extent
> > > ? Exactly.
> > > -- 
> > > Regards,
> > > 
> > > Stephane Faroult
> > > Oriole Ltd
> > > -- 
> > > Please see the official ORACLE-L FAQ: http://www.orafaq.com
> > > -- 
> > > Author: Stephane Faroult
> > >   INET: [EMAIL PROTECTED]
> > > 
> > > 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: [EMAIL PROTECTED] (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: [EMAIL PROTECTED]
> > 
> > Fat City Network Services-- (858) 538-5051  FAX: (858) 538-5051
> > San Diego, California-- Public Internet access / Mailing
> > Lists
> > 
> > To REMOVE your

RE: A rollback segment question on minextents

2002-03-15 Thread Freeman, Robert

Actually the rollback segment header in the first extent exists in a single
block, the rest of the first extent, as I understand it, is available for
undo. Thus making INITIAL and NEXT the same should be of no consequence in
this regard.

It is my understanding (and I'm sure I will be corrected if I'm wrong) the
reason for a requirement of 2 extents is to allow the tail/wrap architecture
that Oracle uses for rollback segments. 

RF

Robert G. Freeman - Oracle8i OCP
Oracle DBA Technical Lead
CSX Midtier Database Administration

The Cigarette Smoking Man: Anyone who can appease a man's conscience can
take his freedom away from him.



-Original Message-
Sent: Friday, March 15, 2002 12:54 PM
To: Multiple recipients of list ORACLE-L


Oracle recommends the size NEXT=INITIAL.
So if I had 10M initial, then most of the initial beyond the 
header info will be wasted? Sure not!

Kumanan

> -Original Message-
> From: Rachel Carmichael [SMTP:[EMAIL PROTECTED]]
> Sent: 11 March 2002 21:48
> To:   Multiple recipients of list ORACLE-L
> Subject:  RE: A rollback segment question on minextents
> 
> the first extent is used by oracle as the segment header to manage the
> transaction information within the rollback segment. The second extent
> contains the actual change vectors
> 
> 
> --- [EMAIL PROTECTED] wrote:
> > Hi,
> > 
> > My point was that it could allocate one more extent as per need. Why
> > the
> > need to minextents = 2?
> > 
> > Thanks
> > Kumanan
> > 
> > > -Original Message-
> > > From: Stephane Faroult [SMTP:[EMAIL PROTECTED]]
> > > Sent: 07 March 2002 20:54
> > > To:   Multiple recipients of list ORACLE-L
> > > Subject:  Re: A rollback segment question on minextents
> > > 
> > > [EMAIL PROTECTED] wrote:
> > > > 
> > > > Hi,
> > > > 
> > > > I was wondering why Oracle force minextents for rollback
> > > > segments to be two. Why can't we have minextents zero or
> > > > no minextents clause at all.
> > > > 
> > > > We can surely set initial extent to be large enough ourselves
> > > > and next extent sized accordingly.
> > > > 
> > > > Can someone enlighten me on the reason/thought behind this?
> > > > 
> > > > Many thanks
> > > > 
> > > > Kumanan Balasundaram
> > > > Database Administrator, IT
> > > > QXL ricardo plc
> > > > www.qxl.com
> > > > P: +44 (0)208 962 7409
> > > 
> > > Oracle doesn't reuse an extent which contains active transactions.
> > What
> > > do you think would happen when you reach the end of your initial
> > extent
> > > ? Exactly.
> > > -- 
> > > Regards,
> > > 
> > > Stephane Faroult
> > > Oriole Ltd
> > > -- 
> > > Please see the official ORACLE-L FAQ: http://www.orafaq.com
> > > -- 
> > > Author: Stephane Faroult
> > >   INET: [EMAIL PROTECTED]
> > > 
> > > 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: [EMAIL PROTECTED] (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: [EMAIL PROTECTED]
> > 
> > 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: [EMAIL PROTECTED] (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).
> 
> 
> __
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RE: A rollback segment question on minextents

2002-03-15 Thread kumanan . balasundaram

While on the subject..
Please see the Oracle Metalink Note: 1029850.6.
It says the first "block" of the first segment contains header 
information.


> -Original Message-
> From: Kumanan Balasundaram 
> Sent: 15 March 2002 17:59
> To:   '[EMAIL PROTECTED]'
> Cc:   '[EMAIL PROTECTED]'
> Subject:      RE: A rollback segment question on minextents
> 
> Oracle recommends the size NEXT=INITIAL.
> So if I had 10M initial, then most of the initial beyond the 
> header info will be wasted? Sure not!
> 
> Kumanan
> 
>   -Original Message-
>   From:   Rachel Carmichael [SMTP:[EMAIL PROTECTED]]
>   Sent:   11 March 2002 21:48
>   To: Multiple recipients of list ORACLE-L
>   Subject:RE: A rollback segment question on minextents
> 
>   the first extent is used by oracle as the segment header to manage
> the
>   transaction information within the rollback segment. The second
> extent
>   contains the actual change vectors
> 
> 
>   --- [EMAIL PROTECTED] wrote:
>   > Hi,
>   > 
>   > My point was that it could allocate one more extent as per need.
> Why
>   > the
>   > need to minextents = 2?
>   > 
>   > Thanks
>   > Kumanan
>   > 
>   > > -Original Message-
>   > > From:   Stephane Faroult [SMTP:[EMAIL PROTECTED]]
>   > > Sent:   07 March 2002 20:54
>   > > To: Multiple recipients of list ORACLE-L
>   > > Subject:Re: A rollback segment question on minextents
>   > > 
>   > > [EMAIL PROTECTED] wrote:
>   > > > 
>   > > > Hi,
>   > > > 
>   > > > I was wondering why Oracle force minextents for rollback
>   > > > segments to be two. Why can't we have minextents zero or
>   > > > no minextents clause at all.
>   > > > 
>   > > > We can surely set initial extent to be large enough ourselves
>   > > > and next extent sized accordingly.
>   > > > 
>   > > > Can someone enlighten me on the reason/thought behind this?
>   > > > 
>   > > > Many thanks
>   > > > 
>   > > > Kumanan Balasundaram
>   > > > Database Administrator, IT
>   > > > QXL ricardo plc
>   > > > www.qxl.com
>   > > > P: +44 (0)208 962 7409
>   > > 
>   > > Oracle doesn't reuse an extent which contains active
> transactions.
>   > What
>   > > do you think would happen when you reach the end of your initial
>   > extent
>   > > ? Exactly.
>   > > -- 
>   > > Regards,
>   > > 
>   > > Stephane Faroult
>   > > Oriole Ltd
>   > > -- 
>   > > Please see the official ORACLE-L FAQ: http://www.orafaq.com
>   > > -- 
>   > > Author: Stephane Faroult
>   > >   INET: [EMAIL PROTECTED]
>   > > 
>   > > 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: [EMAIL PROTECTED] (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
>   > -- 
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&

RE: A rollback segment question on minextents

2002-03-15 Thread kumanan . balasundaram

Oracle recommends the size NEXT=INITIAL.
So if I had 10M initial, then most of the initial beyond the 
header info will be wasted? Sure not!

Kumanan

> -Original Message-
> From: Rachel Carmichael [SMTP:[EMAIL PROTECTED]]
> Sent: 11 March 2002 21:48
> To:   Multiple recipients of list ORACLE-L
> Subject:  RE: A rollback segment question on minextents
> 
> the first extent is used by oracle as the segment header to manage the
> transaction information within the rollback segment. The second extent
> contains the actual change vectors
> 
> 
> --- [EMAIL PROTECTED] wrote:
> > Hi,
> > 
> > My point was that it could allocate one more extent as per need. Why
> > the
> > need to minextents = 2?
> > 
> > Thanks
> > Kumanan
> > 
> > > -Original Message-
> > > From: Stephane Faroult [SMTP:[EMAIL PROTECTED]]
> > > Sent: 07 March 2002 20:54
> > > To:   Multiple recipients of list ORACLE-L
> > > Subject:  Re: A rollback segment question on minextents
> > > 
> > > [EMAIL PROTECTED] wrote:
> > > > 
> > > > Hi,
> > > > 
> > > > I was wondering why Oracle force minextents for rollback
> > > > segments to be two. Why can't we have minextents zero or
> > > > no minextents clause at all.
> > > > 
> > > > We can surely set initial extent to be large enough ourselves
> > > > and next extent sized accordingly.
> > > > 
> > > > Can someone enlighten me on the reason/thought behind this?
> > > > 
> > > > Many thanks
> > > > 
> > > > Kumanan Balasundaram
> > > > Database Administrator, IT
> > > > QXL ricardo plc
> > > > www.qxl.com
> > > > P: +44 (0)208 962 7409
> > > 
> > > Oracle doesn't reuse an extent which contains active transactions.
> > What
> > > do you think would happen when you reach the end of your initial
> > extent
> > > ? Exactly.
> > > -- 
> > > Regards,
> > > 
> > > Stephane Faroult
> > > Oriole Ltd
> > > -- 
> > > Please see the official ORACLE-L FAQ: http://www.orafaq.com
> > > -- 
> > > Author: Stephane Faroult
> > >   INET: [EMAIL PROTECTED]
> > > 
> > > Fat City Network Services-- (858) 538-5051  FAX: (858) 538-5051
> > > San Diego, California-- Public Internet access / Mailing
> > Lists
> > >
> > 
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> > > also send the HELP command for other information (like
> > subscribing).
> > -- 
> > Please see the official ORACLE-L FAQ: http://www.orafaq.com
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> >   INET: [EMAIL PROTECTED]
> > 
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> 
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> -- 
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> -- 
> Author: Rachel Carmichael
>   INET: [EMAIL PROTECTED]
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RE: A rollback segment question on minextents

2002-03-11 Thread Rachel Carmichael

the first extent is used by oracle as the segment header to manage the
transaction information within the rollback segment. The second extent
contains the actual change vectors


--- [EMAIL PROTECTED] wrote:
> Hi,
> 
> My point was that it could allocate one more extent as per need. Why
> the
> need to minextents = 2?
> 
> Thanks
> Kumanan
> 
> > -Original Message-
> > From:   Stephane Faroult [SMTP:[EMAIL PROTECTED]]
> > Sent:   07 March 2002 20:54
> > To: Multiple recipients of list ORACLE-L
> > Subject:Re: A rollback segment question on minextents
> > 
> > [EMAIL PROTECTED] wrote:
> > > 
> > > Hi,
> > > 
> > > I was wondering why Oracle force minextents for rollback
> > > segments to be two. Why can't we have minextents zero or
> > > no minextents clause at all.
> > > 
> > > We can surely set initial extent to be large enough ourselves
> > > and next extent sized accordingly.
> > > 
> > > Can someone enlighten me on the reason/thought behind this?
> > > 
> > > Many thanks
> > > 
> > > Kumanan Balasundaram
> > > Database Administrator, IT
> > > QXL ricardo plc
> > > www.qxl.com
> > > P: +44 (0)208 962 7409
> > 
> > Oracle doesn't reuse an extent which contains active transactions.
> What
> > do you think would happen when you reach the end of your initial
> extent
> > ? Exactly.
> > -- 
> > Regards,
> > 
> > Stephane Faroult
> > Oriole Ltd
> > -- 
> > Please see the official ORACLE-L FAQ: http://www.orafaq.com
> > -- 
> > Author: Stephane Faroult
> >   INET: [EMAIL PROTECTED]
> > 
> > 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: [EMAIL PROTECTED] (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
> -- 
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-- 
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  INET: [EMAIL PROTECTED]

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RE: A rollback segment question on minextents

2002-03-11 Thread kumanan . balasundaram

Hi,

My point was that it could allocate one more extent as per need. Why the
need to minextents = 2?

Thanks
Kumanan

> -Original Message-
> From: Stephane Faroult [SMTP:[EMAIL PROTECTED]]
> Sent: 07 March 2002 20:54
> To:   Multiple recipients of list ORACLE-L
> Subject:  Re: A rollback segment question on minextents
> 
> [EMAIL PROTECTED] wrote:
> > 
> > Hi,
> > 
> > I was wondering why Oracle force minextents for rollback
> > segments to be two. Why can't we have minextents zero or
> > no minextents clause at all.
> > 
> > We can surely set initial extent to be large enough ourselves
> > and next extent sized accordingly.
> > 
> > Can someone enlighten me on the reason/thought behind this?
> > 
> > Many thanks
> > 
> > Kumanan Balasundaram
> > Database Administrator, IT
> > QXL ricardo plc
> > www.qxl.com
> > P: +44 (0)208 962 7409
> 
> Oracle doesn't reuse an extent which contains active transactions. What
> do you think would happen when you reach the end of your initial extent
> ? Exactly.
> -- 
> Regards,
> 
> Stephane Faroult
> Oriole Ltd
> -- 
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> -- 
> Author: Stephane Faroult
>   INET: [EMAIL PROTECTED]
> 
> 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: [EMAIL PROTECTED] (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).
-- 
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Re: A rollback segment question on minextents

2002-03-07 Thread Stephane Faroult

[EMAIL PROTECTED] wrote:
> 
> Hi,
> 
> I was wondering why Oracle force minextents for rollback
> segments to be two. Why can't we have minextents zero or
> no minextents clause at all.
> 
> We can surely set initial extent to be large enough ourselves
> and next extent sized accordingly.
> 
> Can someone enlighten me on the reason/thought behind this?
> 
> Many thanks
> 
> Kumanan Balasundaram
> Database Administrator, IT
> QXL ricardo plc
> www.qxl.com
> P: +44 (0)208 962 7409

Oracle doesn't reuse an extent which contains active transactions. What
do you think would happen when you reach the end of your initial extent
? Exactly.
-- 
Regards,

Stephane Faroult
Oriole Ltd
-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Stephane Faroult
  INET: [EMAIL PROTECTED]

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