Hi,

I have a forms table, a categories table, and a formcategory table which
links the form with the categories it is in.

I automatically set the form_id and category_id in the formcategory table
(that's all it contains) as foreign keys to forms.id and categories.id
respectively. However this automatically creates an index on category_id,
but with a selectivity of 100.

So...will this be problematic in terms of the optimizer? Should I handle
the foreign key stuff myself? It seems like the right thing to
do...but???!

Any advice appreciated,

Cheers,

David