Re: explain.c: why trace PlanState and Plan trees separately?

Yeb Havinga <yebhavinga@gmail.com> writes:
> Will the new referenced expression printing also be used when printing 
> subplans?

> If yes, I do not have to submit the latest version of a patch I made for 
> subplan argument printing (discussed earlier in this thread 
> http://archives.postgresql.org/pgsql-hackers/2010-02/msg01602.php)

Oh, I had forgotten that patch was still in progress.  I think it's
unnecessary given what I'm fooling with.  The attached patch needs
some more testing, but what I get with it is for example

regression=# explain (verbose) select (select oid from pg_class a where
regression(# a.oid = b.relfilenode) from pg_class b;
                                               QUERY PLAN                                               
--------------------------------------------------------------------------------------------------------
 Seq Scan on pg_catalog.pg_class b  (cost=0.00..5556.81 rows=669 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 = b.relfilenode)
(6 rows)

(this is the first example in the above-referenced thread).

			regards, tom lane