Re: Effect of too many columns

On Mon, Apr 12, 2004 at 17:24:17 +0530,
Rajesh Kumar Mallah <mallah(at)trade-india(dot)com> wrote:
>
> Greetings,
>
> Is there any performance penalty of having too many columns in
> a table in terms of read and write speeds.
>
> To order to keep operational queries simple (avoid joins) we plan to
> add columns in the main customer dimension table.
>
> Adding more columns also means increase in concurrency in the table
> as more and more applications will access the same table.
>
> Any ideas if its better to split the table application wise or is it ok?

This is normally a bad idea. If you properly implement constraints in
what is effectively a materialized view, you might end up with a slower
system, depending on your mix of queries. (Generally updating will take
more resources.) So you probably want to test your new design under a
simulated normal load to see if it actually speeds things up in your
case before making the change.