Re: Default ordering option

*Adrian*:
>
> If order is not an issue in the production code why test for it in the
> test code?

In many cases, it would not be a problem in tests if we had an unordered
array comparison helper.
But in other cases, it is a production issue.
In ruby ActiveRecord for exemple, you can do `Patient.find_by(last_name:
'champier')`,
which translates to `SELECT "patients".* FROM "patients" WHERE
"patients"."last_name" = 'champier' LIMIT 1`.
If last_name is not unique, the returned record will be random.

So yes, everything as to be randomized, because the sources are multiples
and the consequences can vary to a dramatic production bug, a failed CI 1%
of the time, or to a useless test assertion.

*Peter*:

> It might be an interesting exercise to implement this as a post-parsing
> hook.

I known nothing about that, but that sounds interesting, do you have any
documentation pointer to help me implement that?

On Wed, Jul 24, 2019 at 10:36 PM Peter Eisentraut <
peter(dot)eisentraut(at)2ndquadrant(dot)com> wrote:

> On 2019-07-23 17:43, Cyril Champier wrote:
> > In this documentation
> > <https://www.postgresql.org/docs/9.1/queries-order.html>, it is said:
> >
> > If sorting is not chosen, the rows will be returned in an
> > unspecified order. The actual order in that case will depend on the
> > scan and join plan types and the order on disk, but it must not be
> > relied on.
> >
> >
> > I would like to know if there is any way to change that to have a "real"
> > random behaviour.
>
> It might be an interesting exercise to implement this as a post-parsing
> hook.
>
> --
> Peter Eisentraut http://www.2ndQuadrant.com/
> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
>