Re: Functional dependencies and GROUP BY

On mån, 2010-07-26 at 10:46 -0600, Alex Hunsaker wrote:
> On Sat, Jul 24, 2010 at 06:23, Peter Eisentraut <peter_e@gmx.net> wrote:
>
> > Another open question I thought of was whether we should put the
> > dependency record on the pg_index row, or the pg_constraint row, or
> > perhaps the pg_class row.  Right now, it is using pg_index, because that
> > was easiest to code up, but I suspect that once we have not-null
> > constraints in pg_constraint, it will be more consistent to make all
> > dependencies go against pg_constraint rather than a mix of several
> > catalogs.
>
> I think for primary keys pg_index is OK.  However for the not-null
> case we have to use pg_constraint... So given that we end up having to
> code that anyways, it seems like it will end up being
> cleaner/consistent to always use the pg_constraint row(s).  So +1 for
> using pg_constraint instead of pg_index from me.

Next version.  Changed dependencies to pg_constraint, removed handling
of unique constraints for now, and made some enhancements so that views
track dependencies on constraints even in subqueries.  Should be close
to final now. :-)