Path: news.easynews.com!core-easynews!newsfeed1.easynews.com!easynews.com!easynews!news-out.nuthinbutnews.com!propagator2-sterling!in.nntp.be!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed.icl.net!newsfeed.fjserv.net!lnewspeer00.lnd.ops.eu.uu.net!lnewspost00.lnd.ops.eu.uu.net!emea.uu.net!not-for-mail From: "Niall Litchfield" Newsgroups: comp.databases.oracle.misc References: <3eb007f1.0304240452.4ece77c1@posting.google.com> Subject: Re: Oracle database mirroring questions Date: Tue, 29 Apr 2003 16:31:26 +0100 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Lines: 32 Message-ID: <3eae9ace$0$4865$ed9e5944@reading.news.pipex.net> NNTP-Posting-Host: host9.audit-commission.gov.uk X-Trace: 1051630286 reading.news.pipex.net 4865 193.128.236.219 X-Complaints-To: abuse@uk.uu.net Xref: core-easynews comp.databases.oracle.misc:97112 X-Received-Date: Tue, 29 Apr 2003 08:30:58 MST (news.easynews.com) "Sybrand Bakker" wrote in message news:aj6gav0p8u66eol2ed5g17qfv4glomtf3v@4ax.com... > On 24 Apr 2003 05:52:03 -0700, sonyantony@hotmail.com (Sony Antony) > wrote: > > >We have been looking at the database redundancy problem from a high > >level point of view, for the purpose of architecturing our distributed > >application. I m not an expert in Oracle. So I decided to ask them > >here before deciding on any particular solution. > > > >1. Does Oracle provide any database replication/mirroring mechanisms, > >so that there will be a warm backup database to take over, if the > >main/primary crashes. If it does what will be the performance hit ( > >cpu usage ) on the primary because this duplication mechanism is > >running in the background. > > > > Standby database in 8i, dataguard in 9i. Ships redolog (changed > bytes). Performance hit should be neglicible. I'd say that the likely performance hit would depend on 1) how stressed your redo system already is and 2) if you are going for the zero dataloss/manadatory redo destination option in which case loss of a link has a certain 'performance impact'. :( -- Niall Litchfield Oracle DBA Audit Commission UK