Re: Larry Ellison comments on Microsoft's benchmark

From: Ivana Humpalot <ivana_humpalot_at_nospam.com>
Date: 2000/07/12
Message-ID: <53Ua5.39284$i5.489528@news1.frmt1.sfba.home.com>#1/1

"Brad" <Brad_at_SeeSigIfThere.com> wrote:

> What I want to know is how the system can still be reliable if one or
> more servers are down. If the data is inaccessible then how can any
> query be reliable? I can understand if there is some striping going on,
> but even then if two machines go down all of the data is not accessible.
> How can the database as a whole be worth hitting if only one of twelve
> servers is up (as Ivana claimed).

Are you asking this question about DB/2, MS SQL Server or Oracle Parallel Server?

If the question is about DB/2 or MS SQL Server then the answer is your query will fail if it needs data on the failed machine.

If your question is about Oracle Parallel Server then the answer is all queries will continue to work, because all machines have access to the shared disks. Unlike DB/2 or MS SQL Server, the database is not subdivided into smaller databases.

In fact, in Oracle Paraller Server, not only will your queries continue to work, the surviving machines will balance the load equally.

In the case of DB/2, MS SQL Server etc you are hosed if one of the machines fails because each machine has a unique portion of the database. You can organize the machines into mutual takeover clusters, but this will not work as well as in Oracle Parallel Server because there is no load balancing. The load perviously carried by the failed machine will have to be taken over by a single machine. If that machine is already running at full capacity then you have a big problem because the machine will be overwhelmed and now you have 2 dead machines instead of one. You can also use failover clustering - i.e., have a backup machine for every machine. Obviously this will drive up costs. Also, the backup machine will be idle until the main machine dies, so this is extremely inefficient use of resources.

In the case of Oracle Parallel Server as you add machines to the cluster, not only will performance go up, but reliability goes up too.

In the case of DB/2 or MS SQL Server, as you add machines to the "cluster", reliability goes DOWN! This is a major flaw. Think twice before adding machines to boost performance, because you are going to get increased downtime. And this ignores downtime due to the fact that in order to add a machine you have to repartition the database.

In short, only Oracle has got it right. Oracle's benchmarks are relevant in the real world, whereas Microsoft's and IBM's benchmarks are laboratory-only benchmarks. Received on Wed Jul 12 2000 - 00:00:00 CDT