Thread: Foreign Keys to Non-primary keys?

Is it possible to have a foreign key to a non-primary key (also meaning non-unique and therefore non-indexed) column i
atable? 

I can only imagine the performance loss...


---
Daniel Åkerud, zilch@home.se

On Thu, 21 Jun 2001 zilch@home.se wrote:

>
> Is it possible to have a foreign key to a non-primary key (also
> meaning non-unique and therefore non-indexed) column i a table?

Generally no.  It's not allowed by the spec, so as of 7.1, we
prevent it. Admittedly, you could pull the rug out from underneath
it by dropping the index, though.