QUERY PLAN
Group (cost=16746.85..16750.36 rows=448 width=18)
Group Key: c.object_type, sub.unreadcount
-> Sort (cost=16746.85..16748.02 rows=467 width=10)
Sort Key: c.object_type, sub.unreadcount
-> Hash Left Join (cost=11896.40..16726.15 rows=467 width=10)
Hash Cond: ((c.object_type)::text = (sub.object_type)::text)
-> Hash Right Join (cost=7734.14..12562.48 rows=467 width=2)
Hash Cond: (uc.comment_id = c.id)
Filter: ((uc.remind_user_id = 5016) OR (c.created_by = 5016))
-> Seq Scan on tbl_unread_comments uc (cost=0.00..4171.06 rows=485 width=8)
Filter: (remind_user_id = 5016)
-> Hash (cost=5414.84..5414.84 rows=133384 width=10)
-> Seq Scan on tbl_comments c (cost=0.00..5414.84 rows=133384 width=10)
Filter: is_system
-> Hash (cost=4162.06..4162.06 rows=16 width=10)
-> Subquery Scan on sub (cost=4160.12..4162.06 rows=16 width=10)
-> Finalize GroupAggregate (cost=4160.12..4161.90 rows=16 width=10)
Group Key: uc_1.object_type
-> Gather Merge (cost=4160.12..4161.68 rows=12 width=10)
Workers Planned: 1
-> Partial GroupAggregate (cost=3160.11..3160.32 rows=12 width=10)
Group Key: uc_1.object_type
-> Sort (cost=3160.11..3160.14 rows=12 width=2)
Sort Key: uc_1.object_type
-> Nested Loop (cost=0.42..3159.89 rows=12 width=2)
-> Parallel Seq Scan on tbl_unread_comments uc_1 (cost=0.00..3033.33 rows=15 width=6)
Filter: ((NOT is_read) AND (remind_user_id = 5016))
-> 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