QUERY PLAN
Group (cost=20840.45..20845.22 rows=636 width=18)
Group Key: c.object_type, sub.unreadcount
-> Sort (cost=20840.45..20842.04 rows=636 width=10)
Sort Key: c.object_type, sub.unreadcount
-> Hash Left Join (cost=16046.02..20810.83 rows=636 width=10)
Hash Cond: ((c.object_type)::text = (sub.object_type)::text)
-> Hash Right Join (cost=11069.85..15832.86 rows=636 width=2)
Hash Cond: (uc.comment_id = c.id)
Filter: ((uc.remind_user_id = 1000) OR (c.created_by = 1000))
-> Gather (cost=1000.00..4874.39 rows=618 width=8)
Workers Planned: 1
-> Parallel Seq Scan on tbl_unread_comments uc (cost=0.00..3812.59 rows=364 width=8)
Filter: (remind_user_id = 1000)
-> Hash (cost=6934.50..6934.50 rows=180348 width=10)
-> Seq Scan on tbl_comments c (cost=0.00..6934.50 rows=180348 width=10)
Filter: is_system
-> Hash (cost=4975.87..4975.87 rows=24 width=11)
-> Subquery Scan on sub (cost=4973.23..4975.87 rows=24 width=11)
-> Finalize GroupAggregate (cost=4973.23..4975.63 rows=24 width=11)
Group Key: uc_1.object_type
-> Gather Merge (cost=4973.23..4975.31 rows=16 width=11)
Workers Planned: 1
-> Partial GroupAggregate (cost=3973.22..3973.50 rows=16 width=11)
Group Key: uc_1.object_type
-> Sort (cost=3973.22..3973.26 rows=16 width=3)
Sort Key: uc_1.object_type
-> Nested Loop (cost=0.42..3972.90 rows=16 width=3)
-> Parallel Seq Scan on tbl_unread_comments uc_1 (cost=0.00..3812.59 rows=19 width=7)
Filter: ((NOT is_read) AND (remind_user_id = 1000))
-> Index Scan using tbl_comments_pkey on tbl_comments c_1 (cost=0.42..8.44 rows=1 width=4)
Index Cond: (id = uc_1.comment_id)
Filter: is_system