QUERY PLAN
Sort (cost=20654.56..20656.31 rows=700 width=18)
Sort Key: c.object_type
-> HashAggregate (cost=20614.49..20621.49 rows=700 width=18)
Group Key: c.object_type, sub.unreadcount
-> Hash Left Join (cost=15420.40..20514.44 rows=20009 width=10)
Hash Cond: ((c.object_type)::text = (sub.object_type)::text)
-> Hash Right Join (cost=7732.27..12765.84 rows=20009 width=2)
Hash Cond: (uc.comment_id = c.id)
Filter: ((uc.remind_user_id = 1005) OR (c.created_by = 1005))
-> Seq Scan on tbl_unread_comments uc (cost=0.00..4165.14 rows=20734 width=8)
Filter: (remind_user_id = 1005)
-> Hash (cost=5413.41..5413.41 rows=133349 width=10)
-> Seq Scan on tbl_comments c (cost=0.00..5413.41 rows=133349 width=10)
Filter: is_system
-> Hash (cost=7687.81..7687.81 rows=25 width=10)
-> Subquery Scan on sub (cost=7680.19..7687.81 rows=25 width=10)
-> Finalize GroupAggregate (cost=7680.19..7687.56 rows=25 width=10)
Group Key: uc_1.object_type
-> Gather Merge (cost=7680.19..7687.19 rows=25 width=10)
Workers Planned: 1
-> Partial GroupAggregate (cost=6680.18..6684.37 rows=25 width=10)
Group Key: uc_1.object_type
-> Sort (cost=6680.18..6681.49 rows=525 width=2)
Sort Key: uc_1.object_type
-> Nested Loop (cost=0.42..6656.46 rows=525 width=2)
-> Parallel Seq Scan on tbl_unread_comments uc_1 (cost=0.00..3029.02 rows=651 width=6)
Filter: ((NOT is_read) AND (remind_user_id = 1005))
-> Index Scan using tbl_comments_pkey on tbl_comments c_1 (cost=0.42..5.57 rows=1 width=4)
Index Cond: (id = uc_1.comment_id)
Filter: is_system