Output affected rows in EXPLAIN

I create a patch that outputs affected rows in EXPLAIN that occur by
INSERT/UPDATE/DELETE.
Despite the fact that commands in EXPLAIN ANALYZE query are executed as
usual, EXPLAIN doesn't show outputting affected rows as in these commands.
The patch fixes this problem.

Examples:
explain analyze insert into a values (1);
QUERY PLAN

------------------------------------------------------------------------------------------
Insert on a (cost=0.00..0.01 rows=0 width=0) (actual time=0.076..0.077
rows=0 loops=1)
-> Result (cost=0.00..0.01 rows=1 width=4) (actual time=0.002..0.002
rows=1 loops=1)
Planning Time: 0.025 ms
Execution Time: 0.412 ms
(4 rows)

INSERT 0 1

QUERY PLAN

------------------------------------------------------------------------------------------------------
Update on a (cost=0.00..35.50 rows=0 width=0) (actual time=0.059..0.060
rows=0 loops=1)
-> Seq Scan on a (cost=0.00..35.50 rows=2550 width=10) (actual
time=0.012..0.013 rows=7 loops=1)
Planning Time: 0.142 ms
Execution Time: 0.666 ms
(4 rows)

UPDATE 7

explain analyze delete from a where n = 1;
QUERY PLAN

---------------------------------------------------------------------------------------------------
Delete on a (cost=0.00..41.88 rows=0 width=0) (actual time=0.147..0.147
rows=0 loops=1)
-> Seq Scan on a (cost=0.00..41.88 rows=13 width=6) (actual
time=0.120..0.123 rows=7 loops=1)
Filter: (n = 1)
Planning Time: 1.073 ms
Execution Time: 0.178 ms
(5 rows)

DELETE 7

EXPLAIN queries without ANALYZE don't affect rows, so the output number is
0.

explain update a set n = 2;
QUERY PLAN
------------------------------------------------------------
Update on a (cost=0.00..35.50 rows=0 width=0)
-> Seq Scan on a (cost=0.00..35.50 rows=2550 width=10)
(2 rows)

UPDATE 0

Maybe there is no need to add this row when EXPLAIN has no ANALYZE. So it
is a discussion question.
Also haven't fixed regress tests yet.

Regards,
Damir Belyalov
Postgres Professional