plan.txt
text/plain
test2=# EXPLAIN SELECT * FROM (SELECT * FROM t ORDER BY a) foo ORDER BY a, b;
QUERY PLAN
------------------------------------------------------------------------
Incremental Sort (cost=147027.04..269419.25 rows=1000000 width=20)
Sort Key: t.a, t.b
Presorted Key: t.a
-> Sort (cost=136537.84..139037.84 rows=1000000 width=20)
Sort Key: t.a
-> Seq Scan on t (cost=0.00..16370.00 rows=1000000 width=20)
(6 rows)