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RE: Oracle RAC cost justification?

From: Marquez, Chris <cmarquez_at_collegeboard.org>
Date: Mon, 6 Jun 2005 13:12:43 -0400
Message-ID: <B30C2483766F9342B6AEF108833CC84E0450BBFA@ecogenemld50.Org.Collegeboard.local>


Raj,
>>so the way implemented TAF, it is seamless for us
What is the client app;
SQL*Net
ODBC
JDBC (Think/OCI)?

Tapan,

>>'true TAF' i.e. TAF that works with updates, deletes and inserts
>> I don't see how a business can do just selects
>> and be OK justifying the cost of RAC.

This is not a RAC issue it is an Oracle Database design issue...you are asking to have all transactions continue and commit after failure. This will probably and correctly never happen. Think about it, if any Oracle database node fails you *want* and Oracle will rollback uncommitted transactions (on startup)...the surviving node in RAC dose this same thing. It would be nice if we could tell Oracle to commit all transactions on startup after a server crash, but almost no one would use an option like this. It would likely mean data inconsistency for any application that was in the middle of a transaction at the time of failure...which is where most sessions/transaction are when a server fails.

Chris Marquez
Oracle DBA

-----Original Message-----
From: oracle-l-bounce_at_freelists.org on behalf of rjamya Sent: Sun 6/5/2005 9:52 PM
To: Tapan Trivedi
Cc: Oracle Discussion List
Subject: Re: Oracle RAC cost justification?  

Tapan,
We start loosing money if users can't select stuff from the database. We have background processes that use AQ based mechanism to upload processed data. Most of our applications perform selects (a lot of them with sub-second response time), so the way implemented TAF, it is seamless for us and our users. Heck over 95% of them don't even know it is a RAC system with two nodes. They rarely see connection error messages, since we pre-connect for critical sessions.

Raj

On 6/5/05, Tapan Trivedi <taptriv_at_yahoo.com> wrote:
>
> Has anyone implemented 'true TAF' i.e. TAF that works with updates,
> deletes and inserts as opposed to just selects. I know it is not supported
> but there are ways around it. Has anyone done it. I don't see how a business
> can do just selects and be OK justifying the cost of RAC.
> Does anyone have an application that does JUST SELECTS then it will be a
> true Transparent Application Failover - does anyone ? Raj, can you maybe
> discuss a little bit about the way your application works ?
> Tapan Trivedi
>

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Received on Mon Jun 06 2005 - 13:18:36 CDT

Original text of this message

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