Re: Inconsistency in plpgsql's error context reports

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Mon, Dec 11, 2017 at 3:52 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Here's a quick hack at that. I guess the main question that needs to be
>> asked is whether we're happy with plpgsql getting so much chattier
>> (as per all the regression test changes).

> I confess to never having really grokked, even in the pre-patch state,
> why we sometimes get an "SQL statement" context line and sometimes
> not. However, what strikes me about this is that the SQL statement is
> a completely fabricated one that the user never entered.

I spent a brief amount of time looking at whether we could hide the
"fabricated statements" more thoroughly, and decided that it would
be a lot more work than seems warranted, and there would likely be
holes in it anyway. It's not like we don't document this behavior:
the plpgsql introductory material says

All expressions used in PL/pgSQL statements are processed using
the server's main SQL executor. For example, when you write a
PL/pgSQL statement like

IF expression THEN ...

PL/pgSQL will evaluate the expression by feeding a query like

SELECT expression

to the main SQL engine.

https://www.postgresql.org/docs/devel/static/plpgsql-expressions.html

So basically my conclusion at this point is that I'm not willing
to do any more work on this than the patch I already proposed.
If you want to do something more invasive, have at it.

regards, tom lane