Explain Join with indexes

explain-join-2.sql

EXPLAIN
  SELECT posts.*, comments.*
   FROM posts LEFT JOIN comments
   ON posts.id = comments.post_id;

# Before adding indexes

                               QUERY PLAN
------------------------------------------------------------------------
 Hash Right Join  (cost=394.50..2589.00 rows=50000 width=150)
   Hash Cond: (comments.post_id = posts.id)
   ->  Seq Scan on comments  (cost=0.00..1257.00 rows=50000 width=72)
   ->  Hash  (cost=257.00..257.00 rows=11000 width=78)
         ->  Seq Scan on posts  (cost=0.00..257.00 rows=11000 width=78)

# After adding indexes
                               QUERY PLAN
------------------------------------------------------------------------
 Hash Right Join  (cost=394.50..2589.00 rows=50000 width=150)
   Hash Cond: (comments.post_id = posts.id)
   ->  Seq Scan on comments  (cost=0.00..1257.00 rows=50000 width=72)
   ->  Hash  (cost=257.00..257.00 rows=11000 width=78)
         ->  Seq Scan on posts  (cost=0.00..257.00 rows=11000 width=78)