Re: postgresql clustering

On 9/29/05, Tino Wildenhain <tino(at)wildenhain(dot)de> wrote:
>
> Well, I dont know why many people believe parallel execution
> automatically means high performance. Actually most of the time
> the performance is much worser this way.
> If your dataset remains statically and you do only read-only
> requets, you get higher performance thru load-balancing.
> If howewer you do some changes to the data, the change has to
> be propagated to all nodes - which in fact costs performance.
> This highly depends on the link speed between the nodes.

I think you should clarify that the type of clustering you're discussing is
the, "shared-nothing" model which is most prevalent in open-source
databases. Shared-disk and shared-memory clustered systems do not have the
"propagation" issue but do have others (distributed lock manager, etc).
Don't make blind statements. If you want more information about "real-world"
clustering, read the research for DB2 (Mainframe) and Oracle RAC.

--
Respectfully,

Jonah H. Harris, Database Internals Architect
EnterpriseDB Corporation
http://www.enterprisedb.com/