Re: BUG #13789: pg_admin produces table definitiona instead of a view

Tom,

Thanks for reply. I only noticed this during DB restore process where I was
getting an error on the line "CREATE TABLE my_view ...". From what I see,
this view was never restored.

thanks,
Alex

On Wed, Dec 2, 2015 at 9:42 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> amsl(dot)sm(at)gmail(dot)com writes:
> > I have a view defined with the following sql statement:
>
> > CREATE OR REPLACE VIEW my_view AS
> > (
> > select s.id as start_id
> > from start s
> > group by s.id
> > order by start_date desc
> > );
>
> Note that this view definition isn't even legal unless start.id is
> a primary key, otherwise you get
>
> ERROR: column "s.start_date" must appear in the GROUP BY clause or be
> used in an aggregate function
>
> > When pg_admin exports this view it outputs it as as table not view:
>
> > CREATE TABLE my_view (
> > start_id integer
> > );
>
> This is not a bug; if you look further down you'll find something like
>
> CREATE RULE "_RETURN" AS
> ON SELECT TO my_view DO INSTEAD SELECT s.id AS start_id
> FROM start s
> GROUP BY s.id
> ORDER BY s.start_date DESC;
>
> which converts the table to a view (admittedly in a not-very-obvious way).
> Because of the dependency on start's primary key, the view can't simply
> be defined up at the top of the dump. This is how pg_dump chooses to
> break the circularity.
>
> regards, tom lane
>