On Mon, Apr 29, 2013 at 7:31 PM, Tom Lane wrote:
> Ashutosh Bapat writes:
> > Is there any reason why do we want to check the functional dependencies
> at
> > the time of parsing and not after rewrite? Obviously, by doing so, we
> will
> > allow creation of certain views which will start throwin
Ashutosh Bapat writes:
> Is there any reason why do we want to check the functional dependencies at
> the time of parsing and not after rewrite? Obviously, by doing so, we will
> allow creation of certain views which will start throwing errors after the
> underlying table changes the primary key.
> Can you please elaborate, why would it be a disaster?
>
> Consider that we've done
>
> create table t1 (id int primary key, ... other stuff ...);
> create view v1 as select * from t1;
> create view v2 as select * from v1 group by id;
>
> Currently, v2 would be rejected but you would like to make
Ashutosh Bapat writes:
> On Fri, Apr 26, 2013 at 7:54 PM, Tom Lane wrote:
>> A larger point is that the patch as proposed doesn't fix the stated
>> problem, because it only descends into written-out subqueries. It
>> would only succeed at looking into views if we applied it after
>> rewriting, r
On Fri, Apr 26, 2013 at 7:54 PM, Tom Lane wrote:
> Ashutosh Bapat writes:
> > The reason being, it doesn't look into the subqueries (in FROM clause) to
> > infer that p.product_id is essentially product.product_id which is a
> > primary key.
>
> Right.
>
> > Attached find a crude patch to infer
Ashutosh Bapat writes:
> The reason being, it doesn't look into the subqueries (in FROM clause) to
> infer that p.product_id is essentially product.product_id which is a
> primary key.
Right.
> Attached find a crude patch to infer the same by traversing subqueries.
I think this is probably a ba
Hi All,
If group by clause has primary key, the targetlist may have columns which
are not part of the aggregate and not part of group by clause. The relevant
commit is e49ae8d3bc588294d07ce1a1272b31718cfca5ef and relevant mail thread
has subject Functional dependencies and GROUP BY.
As a result, f
