Re: Underlying file structure Was: IBM i 7.2 & Power8

[Alan Campin <alan0307d@xxxxxxxxx>]

Not correct. You only have the issue if you create new indexes. That was
what John was talking about. If you create a field select logical using an
existing index there is no cost except the format object on the disk.
Underneath both use the same index sub-object and sequential I/O runs a lot
faster.


On Fri, Apr 25, 2014 at 2:58 PM, <rob@xxxxxxxxx> wrote:

> The reason some people felt it was bad was probably because the more LF's
> you had then the more overhead occurred.
> Decades and decades ago John Sears used to have seminars on just this.
> Then some "names" said it's no longer the impact it used to be. Especially
> after version such-and-such.
> Other people said that, in the real world, they still had multiple
> examples of excessive LFs hurting performance.
>
>
>
> Rob Berendt
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