Re: Declarative partitioning - another take

On Fri, Oct 28, 2016 at 3:53 AM, Amit Langote
<Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> wrote:
> [ new patches ]

Reviewing 0005:

Your proposed commit messages says this:

> If relation is the target table (UPDATE and DELETE), flattening is
> done regardless (scared to modify inheritance_planner() yet).

In the immortal words of Frank Herbert: “I must not fear. Fear is the
mind-killer. Fear is the little-death that brings total obliteration.
I will face my fear. I will permit it to pass over me and through me.
And when it has gone past I will turn the inner eye to see its path.
Where the fear has gone there will be nothing. Only I will remain.”

In other words, I'm not going to accept fear as a justification for
randomly-excluding the target-table case from this code. If there's
an actual reason not to do this in that case or some other case, then
let's document that reason. But weird warts in the code that are
justified only by nameless anxiety are not good.

Of course, the prior question is whether we should EVER be doing this.
I realize that something like this MAY be needed for partition-wise
join, but the mission of this patch is not to implement partition-wise
join. Does anything in this patch series really require this? If so,
what? If not, how about we leave it out and refactor it when that
change is really needed for something?

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company