From oracle-l-bounce@freelists.org Mon Aug 22 08:56:45 2005 Return-Path: Received: from air891.startdedicated.com (root@localhost) by orafaq.com (8.12.10/8.12.10) with ESMTP id j7MDujTW018936 for ; Mon, 22 Aug 2005 08:56:45 -0500 X-ClientAddr: 206.53.239.180 Received: from turing.freelists.org (freelists-180.iquest.net [206.53.239.180]) by air891.startdedicated.com (8.12.10/8.12.10) with ESMTP id j7MDuVIP018885 for ; Mon, 22 Aug 2005 08:56:31 -0500 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 0C24D1E5726; Mon, 22 Aug 2005 08:56:22 -0500 (EST) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 13460-08; Mon, 22 Aug 2005 08:56:21 -0500 (EST) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 73EBA1E5745; Mon, 22 Aug 2005 08:56:21 -0500 (EST) Message-ID: <4FF77D01E13B214590F4FA3E2C3021D003DE027A@pecos.csw.alewife.net> From: Sarah Satterthwaite To: oracle-l@freelists.org Subject: RE: MultiMaster Replication Date: Mon, 22 Aug 2005 09:54:27 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C5A721.02E33050" X-OriginalArrivalTime: 22 Aug 2005 13:54:29.0438 (UTC) FILETIME=[04182DE0:01C5A721] X-archive-position: 24280 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-To: oracle-l-bounce@freelists.org X-original-sender: ssatterthwaite@cswcasa.com Precedence: normal Reply-To: ssatterthwaite@cswcasa.com X-list: oracle-l X-Virus-Scanned: by amavisd-new-20030616-p9 (Debian) at avenirtech.net X-mailscan-MailScanner-Information: Please contact the ISP for more information X-mailscan-MailScanner: Found to be clean X-MailScanner-From: oracle-l-bounce@freelists.org X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on air891.startdedicated.com X-Spam-Status: No, hits=-3.6 required=5.0 tests=AWL,BAYES_00, HTML_FONTCOLOR_BLUE,HTML_MESSAGE autolearn=no version=2.63 ------_=_NextPart_001_01C5A721.02E33050 Content-Type: text/plain; charset="iso-8859-1" Faud, I've done a lot of experimenting with various flavors of Replication in recent months. 1. I didn't test taking down the master definition site, but if one of the other sites goes down, transactions just queue up until it is available again. It handled it very nicely. I expect that the same would happen if the master definition site went down, but you should test it (and let us know the results). 2. Sequences can not be replicated like table data. There seem to be two ways to handle sequences: a. Use different ranges of the sequence at each site. Be careful that the ranges are large enough that a database will not run out of values in its range. b. Use a different modulus for each database to generate unique values. So, if you have 3 databases you could have the first start with 0, the second start with 1 and the third start with 2. All would be incremented by 3. Sarah Satterthwaite -----Original Message----- From: Fuad Arshad [mailto:fuadar@yahoo.com] Sent: Sunday, August 21, 2005 10:19 AM To: oracle-l@freelists.org Subject: MultiMaster Replication I've been reading up on multimaster replication and had a few questions. 1. After the multimaster replication setup there needs to be a master definition site. if the communication breaks between 2 sites will we have to change the master definition site. 2. the tables the i'm trying to replicate have sequences that i need to transform to sequences on the other side. oracle seems to say its possbile but i cant find an example. If anyone on the list has had experience with multimaster. if they could drop me an email and we could chat a little bit offline that would be really great. ------_=_NextPart_001_01C5A721.02E33050 Content-Type: text/html; charset="iso-8859-1"

Faud,

I've done a lot of experimenting with various flavors of Replication in recent months.

1. I didn't test taking down the master definition site, but if one of the other sites goes down, transactions just queue up until it is available again. It handled it very nicely. I expect that the same would happen if the master definition site went down, but you should test it (and let us know the results).

2. Sequences can not be replicated like table data. There seem to be two ways to handle sequences:

a. Use different ranges of the sequence at each site. Be careful that the ranges are large enough that a database will not run out of values in its range.

b. Use a different modulus for each database to generate unique values. So, if you have 3 databases you could have the first start with 0, the second start with 1 and the third start with 2. All would be incremented by 3.

Sarah Satterthwaite

-----Original Message-----
From: Fuad Arshad [mailto:fuadar@yahoo.com]
Sent: Sunday, August 21, 2005 10:19 AM
To: oracle-l@freelists.org
Subject: MultiMaster Replication

I've been reading up on multimaster replication and had a few questions.

1. After the multimaster replication setup there needs to be a master definition site. if the communication breaks between 2 sites will we have to change the master definition site.

2. the tables the i'm trying to replicate have sequences that i need to transform to sequences on the other side.

oracle seems to say its possbile but i cant find an example.

If anyone on the list has had experience with multimaster. if they could drop me an email and we could chat a little bit offline that would be really great.

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