Re: Larry Ellison comments on Microsoft's benchmark

Ivana Humpalot wrote:

> "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.

I believed DB/2 Parallel edition worked like ORACLE Parallel Server with share database.
But you say that it's rather like MS with splintered databases. Am I right ?

--
My best regards,
Vitaly Lipovetsky.
Deputy head of IT division
First Ukrainian Intl bank

Brainbench(Tekmetrix) e-certification id 14050 SYBASE DBA 4.38
Brainbench(Tekmetrix) e-certification id 14050 MS SQL Server DBA 4.51