Hi Helen,

> At 10:25 AM 21/10/2003 +0200, you wrote:
> >Well the problem is that I have a few (5 or 6) small tables with few
> >values. From what I understand from Helen, this means that the index
> >selectivity is low, and hence that there will be a substantial

performance

> >degradation. Here comments on my original foreign key structure left me

in

> >no doubt whatsoever that it was a VERY BAD IDEA. :-D
>
> It's still a VERY BAD IDEA to put referential constraints referencing your
> low-count lookup tables. Lots of good things have happened to optimizer -
> great, great things - but this isn't an optimizer problem. It has to do
> with the index trees that are built for these indexes and the resulting
> enormous delays.

I thought that the optimizer would also use these indices when doing SELECTs
while it should use others instead. This should be fixed now, right?


Anyway, the index issue is a problem :-)


With regards,

Martijn Tonies
Database Workbench - developer tool for InterBase, Firebird & MS SQL Server.
Upscene Productions
http://www.upscene.com