Re: explain and PARAM_EXEC

On Fri, Feb 19, 2010 at 10:22 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> So I guess there are two issues here: (1) somehow I feel like we
>> should be telling the user what expression is being used to initialize
>> $0, $1, etc. when they are PARAM_EXEC parameters;
>
> Maybe, but the only reasonable place to put it would be within the
> (SubPlan N) reference, which is not a place where verboseness would be
> appreciated, I think.  In principle it could look something like
>
>        (SubPlan N ($0 := b.oid))
>

what if we put fully qualified names every time we use a reference
from a subplan?
something like:

QUERY PLAN
--------------------------------------------------------------------------------------------------------
Seq Scan on pg_catalog.pg_class b (cost=0.00..2250.22 rows=271 width=4)
Output: (SubPlan 1)
SubPlan 1
-> Index Scan using pg_class_oid_index on pg_catalog.pg_class a
(cost=0.00..8.27 rows=1 width=4)
Output: a.oid
Index Cond: (a.oid = subplan1.$0)

--
Atentamente,
Jaime Casanova
Soporte y capacitación de PostgreSQL
Asesoría y desarrollo de sistemas
Guayaquil - Ecuador
Cel. +59387171157