On Wed, 6 Aug 2003, Tom Lane wrote:
> "scott.marlowe" <scott.marlowe@ihs.com> writes:
> > On Wed, 6 Aug 2003, Tom Lane wrote:
> >> One obvious question is whether you have your foreign keys set up
> >> efficiently in the first place. As a rule, the referenced and
> >> referencing columns should have identical datatypes and both should
> >> be indexed. (PG will often let you create foreign key constraints
> >> that don't meet these rules ... but performance will suffer.)
>
> > Is this one of those things that should spit out a NOTICE when it happens?
> > I.e. when a table is created with a references and uses a different type
> > than the parent, would it be a good idea to issue a "NOTICE: parent and
> > child fields are not of the same type"
>
> I could see doing that for unequal data types, but I'm not sure if it's
> reasonable to do it for lack of index. Usually you won't have created
> the referencing column's index yet when you create the FK constraint,
> so any warning would just be noise. (The referenced column's index *is*
> checked for, since we require it to be unique.)
Sure. I wasn't thinking of the index issue anyway, just the type
mismatch.
