Return-Path: Delivered-To: 2-oracle-l@orafaq.com Received: (qmail 17452 invoked from network); 20 Dec 2007 13:33:22 -0600 Received: from freelists-180.iquest.net (HELO turing.freelists.org) (206.53.239.180) by static-ip-69-64-49-119.inaddr.intergenia.de with SMTP; 20 Dec 2007 13:33:22 -0600 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id D34947DDAEC; Thu, 20 Dec 2007 14:33:22 -0500 (EST) 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 16796-08; Thu, 20 Dec 2007 14:33:22 -0500 (EST) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 4B6187DD66D; Thu, 20 Dec 2007 14:33:22 -0500 (EST) Received: with ECARTIS (v1.0.0; list oracle-l); Thu, 20 Dec 2007 13:45:58 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 43D877DB4C4 for ; Thu, 20 Dec 2007 13:45:58 -0500 (EST) 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 10232-08 for ; Thu, 20 Dec 2007 13:45:58 -0500 (EST) Received: from corrly01.jabil.com (corrly01.jabil.com [198.51.174.16]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id ACB4D7DC425 for ; Thu, 20 Dec 2007 13:45:57 -0500 (EST) X-IronPort-AV: E=Sophos;i="4.24,190,1196658000"; d="scan'208,217";a="111244875" Received: from unknown (HELO CORCON02.corp.jabil.org) ([172.31.10.200]) by corrly01.jabil.com with ESMTP; 20 Dec 2007 13:45:55 -0500 Received: from ALFCON01.corp.jabil.org ([172.31.10.199]) by CORCON02.corp.jabil.org with Microsoft SMTPSVC(6.0.3790.1830); Thu, 20 Dec 2007 13:45:55 -0500 Received: from ALFARSCON01.corp.jabil.org ([172.31.12.56]) by ALFCON01.corp.jabil.org with Microsoft SMTPSVC(6.0.3790.1830); Thu, 20 Dec 2007 13:45:55 -0500 Received: from alfarsmsg07.corp.jabil.org ([172.31.12.53]) by ALFARSCON01.corp.jabil.org with Microsoft SMTPSVC(6.0.3790.1830); Thu, 20 Dec 2007 13:45:55 -0500 X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C84338.8DCC3D9E" Subject: RE: Do selects block truncates? Date: Thu, 20 Dec 2007 13:45:54 -0500 Message-ID: In-Reply-To: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: Do selects block truncates? References: <607D6181D9919041BE792D70EF2AEC482434DC@LIMENS.sivsa.int> From: "Tony Aponte" To: "oracle-l" X-OriginalArrivalTime: 20 Dec 2007 18:45:55.0745 (UTC) FILETIME=[8DDE6110:01C84338] X-archive-position: 4051 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-to: oracle-l-bounce@freelists.org X-original-sender: Tony_Aponte@Jabil.com Precedence: normal Reply-to: Tony_Aponte@Jabil.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 X-Virus-Scanned: Debian amavisd-new at localhost.localdomain ------_=_NextPart_001_01C84338.8DCC3D9E Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Could it be that the reader is part of an XA transaction? I think I remember a paper or presentation by one of the Wise Men detailing how a reader that's part of a distributed transaction can block others simply by executing a Select. =20 Tony Aponte =20 ________________________________ From: oracle-l-bounce@freelists.org [mailto:oracle-l-bounce@freelists.org] On Behalf Of Jared Still Sent: Thursday, December 20, 2007 1:15 PM To: genegurevich@discover.com Cc: oracle-l Subject: Re: Do selects block truncates? =20 On Dec 20, 2007 9:43 AM, wrote: =09 I am running oracle 10.2.0.2 and I see two sessions running truncate commands being stuck. It looks like they are waiting on another session which is currently running a long select. That=20 select accesses both of the tables that the other two sessions are trying to truncate. I was not aware that a select can block a truncate. Is that the case or is there something else here which I am missing? I don't believe that the SELECT is blocking the truncate. This is easy to test.=20 In session 1: drop table rbg; create table rbg as select * from dba_objects=20 / insert /*+ append */ into rbg select * from rbg; commit; insert /*+ append */ into rbg select * from rbg; commit; insert /*+ append */ into rbg select * from rbg;=20 commit; insert /*+ append */ into rbg select * from rbg; commit; In session 2: select * from rbg; Back to session 1: truncate table rbg; Back to session 2: PUBLIC /588bb8e2_ObjectStreamField 30790 SYNONYM 08/14/2006 14:37:42 04/13/2007 17:59:12 2006-08-14:14:37:42 VALID N N N ERROR: ORA-08103: object no longer exists=20 22700 rows selected. This is on 10.2.0.3 --=20 Jared Still Certifiable Oracle DBA and Part Time Perl Evangelist ------_=_NextPart_001_01C84338.8DCC3D9E Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Could it be that the reader is part = of an XA transaction?  I think I remember a paper or presentation by one = of the Wise Men detailing how a reader that’s part of a distributed = transaction can block others simply by executing a Select.

 

Tony = Aponte

 

From: = oracle-l-bounce@freelists.org [mailto:oracle-l-bounce@freelists.org] On Behalf Of Jared Still
Sent: Thursday, December = 20, 2007 1:15 PM
To: = genegurevich@discover.com
Cc: oracle-l
Subject: Re: Do selects = block truncates?

 

On Dec 20, 2007 9:43 AM, <genegurevich@discover.com&g= t; wrote:


I am running oracle 10.2.0.2 and I see two sessions running truncate
commands being stuck. It looks like they are
waiting on another session which is currently running a long select. = That
select accesses both of the tables that
the other two sessions are trying to truncate. I was not aware that = a
select can block a truncate. Is that the case
or is there something else here which I am = missing?


I don't believe that the SELECT is blocking the truncate.

This is easy to test.

In session 1:

drop table rbg;

create table rbg
as
select *
from
dba_objects
/

insert /*+ append */
into rbg
select * from rbg;

commit;

insert /*+ append */
into rbg
select * from rbg;

commit;

insert /*+ append */
into rbg
select * from rbg;

commit;

insert /*+ append */
into rbg
select * from rbg;

commit;

In session 2:

select * from rbg;

Back to session 1:
truncate table rbg;

Back to session 2:

PUBLIC     /588bb8e2_ObjectStreamField       &nbs= p;            = ;            =         30790
SYNONYM           =   08/14/2006 14:37:42 04/13/2007 17:59:12 2006-08-14:14:37:42 = VALID   N N N

ERROR:
ORA-08103: object no longer exists

22700 rows selected.

This is on 10.2.0.3


--
Jared Still
Certifiable Oracle DBA and Part Time Perl = Evangelist

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