Received: (qmail 19667 invoked from network); 7 Jul 2011 10:27:27 -0500 Received: from freelists-180.iquest.net (HELO turing.freelists.org) (206.53.239.180) by static-ip-85-25-126-90.inaddr.intergenia.de with SMTP; 7 Jul 2011 10:27:10 -0500 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 24793E32C83; Thu, 7 Jul 2011 11:26:29 -0400 (EDT) X-Virus-Scanned: Debian amavisd-new at localhost.localdomain Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing.freelists.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id FDgE4WxUV2gy; Thu, 7 Jul 2011 11:26:28 -0400 (EDT) Received: from turing.freelists.org (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id EF1DCE32C39; Thu, 7 Jul 2011 11:25:45 -0400 (EDT) Received: with ECARTIS (v1.0.0; list oracle-l); Thu, 07 Jul 2011 11:25:04 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 34526E32C0D for ; Thu, 7 Jul 2011 11:25:04 -0400 (EDT) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing.freelists.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id REVoD7tCYdhh for ; Thu, 7 Jul 2011 11:25:04 -0400 (EDT) Received: from troll.tpk.net (troll.tpk.net [216.107.198.11]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id E9906E31B0B for ; Thu, 7 Jul 2011 11:25:03 -0400 (EDT) Received: from mwf4500 (c-75-69-96-73.hsd1.nh.comcast.net [75.69.96.73]) by troll.tpk.net (8.14.2/8.12.11) with ESMTP id p67FP0TH006822; Thu, 7 Jul 2011 11:25:01 -0400 From: "Mark W. Farnham" To: , , "'Oracle-L Freelists'" References: In-Reply-To: Subject: RE: What is the purpose of segment level checkpoint before DROP/TRUNCATE of a table? Date: Thu, 7 Jul 2011 11:25:09 -0400 Message-ID: <016b01cc3cba$0fb4ea00$2f1ebe00$@rsiz.com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_016C_01CC3C98.88A34A00" Content-Language: en-us X-archive-position: 37284 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-to: oracle-l-bounce@freelists.org X-original-sender: mwf@rsiz.com Precedence: normal Reply-To: mwf@rsiz.com List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: oracle-l X-List-ID: oracle-l List-subscribe: List-owner: List-post: List-archive: X-list: oracle-l ------=_NextPart_000_016C_01CC3C98.88A34A00 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit I added my comments on Tanel's blog. From: oracle-l-bounce@freelists.org [mailto:oracle-l-bounce@freelists.org] On Behalf Of Tanel Poder Sent: Wednesday, July 06, 2011 4:59 AM To: yparesh@gmail.com; Oracle-L Freelists Subject: Re: What is the purpose of segment level checkpoint before DROP/TRUNCATE of a table? I started writing a reply here, but thought others would benefit from it as well, so turned the answer into a blog entry: http://blog.tanelpoder.com/2011/07/06/what-is-the-purpose-of-segment-level-c heckpoint-before-droptruncate-of-a-table/ This is just my reasoning, there may be other, more fundmental reasons behind it. -- Tanel Poder http://blog.tanelpoder.com On Wed, Jul 6, 2011 at 4:30 AM, Paresh Yadav wrote: Hi, What is the purpose of segment level checkpoint before DROP/TRUNCATE of a table? I have tried to find this since quite some time, Only thing I have found is that it is required for recoverability, specifically point in time recovery amongst many other things. I have read about it on so many sites (as far as I remember Jonathan Lewis, Tom Kyte etc.). I recently saw an awesome article on check points by Harald Van Breederode titled "What's the Point of Oracle Checkpoints?". How does it help in recoverability? I thought about point-in-time recovery. All the information to recover dirty buffers for committed transactions should be in the redo stream (redo log and/or archived log) so why do a checkpoint at the object level before truncat//drop? Is it to shorten MTTR etc.? An explanation will be very much appreciated. Any pointers to other resources that I can read in this matter? -- Thanks Paresh 416-688-1003 ------=_NextPart_000_016C_01CC3C98.88A34A00 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

I added my comments on Tanel’s blog.

 

From:= = oracle-l-bounce@freelists.org [mailto:oracle-l-bounce@freelists.org] = On Behalf Of Tanel Poder
Sent: Wednesday, July 06, 2011 = 4:59 AM
To: yparesh@gmail.com; Oracle-L = Freelists
Subject: Re: What is the purpose of segment level = checkpoint before DROP/TRUNCATE of a table?

 

I started writing a reply here, but thought others = would benefit from it as well, so turned the answer into a blog = entry:

 

 

This is just my reasoning, there may be other, more = fundmental reasons behind it.

 

--

Tanel = Poder

 

 

On Wed, = Jul 6, 2011 at 4:30 AM, Paresh Yadav <yparesh@gmail.com> = wrote:

Hi,


What is the purpose of segment level checkpoint = before DROP/TRUNCATE of a table? I have tried to find this since = quite some time, Only thing I have found is that it is required for = recoverability, specifically point in time = recovery amongst many other things.  I have read about it = on so many sites (as far as I remember Jonathan Lewis, Tom Kyte etc.). I = recently saw an awesome article on check points by Harald Van = Breederode titled  "What's the Point of  Oracle = Checkpoints?". How does it help in recoverability? I thought = about point-in-time recovery. All the information to recover dirty = buffers for committed transactions should be in the redo = stream (redo log and/or archived log) so why do a checkpoint at the = object level before truncat//drop? Is it to shorten MTTR etc.? An = explanation will be very much appreciated. Any pointers to other = resources that I can read in this matter?

--
Thanks
Paresh
416-688-1003=

 

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