Re: Functional dependencies and GROUP BY

On Sat, Jul 24, 2010 at 06:23, Peter Eisentraut <peter_e(at)gmx(dot)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.