At 11:28 AM 17/09/2004 +0100, you wrote:

>Alain PIERRE wrote:
>
> > Q6: Is there some rule of thumb/calculation rule to make
> > up whether a table is to be considered as a lookup table or
> > not. A threshold value of the index selectivity ?

It's not a question of whether a table should be considered a lookup table
or not.

It's a question of how many values are distributed in the foreign keys of
tables that use small lookup tables. You can make a table a lookup table
without pointing a foreign key at it.

Make use of gstat to look at these FK indexes. Assess the performance on
reality simulations.

./heLen

>I have a few hundred entries in mine, but then I allow typing in the
>start of a town to find a name. Too large a lookup table for a drop down
>list, and you scroll for hours ;)
>
>--
>Lester Caine
>-----------------------------
>L.S.Caine Electronic Services
>
>
>
>
>Yahoo! Groups Links
>
>
>
>