QUERY PLAN
Group (cost=18758.69..18774.31 rows=700 width=18)
Group Key: c.object_type, sub.unreadcount
-> Sort (cost=18758.69..18763.89 rows=2083 width=10)
Sort Key: c.object_type, sub.unreadcount
-> Hash Left Join (cost=13423.50..18643.87 rows=2083 width=10)
Hash Cond: ((c.object_type)::text = (sub.object_type)::text)
-> Hash Right Join (cost=8485.57..13699.64 rows=2083 width=2)
Hash Cond: (uc.comment_id = c.id)
Filter: ((uc.remind_user_id = 5388) OR (c.created_by = 5388))
-> Seq Scan on tbl_unread_comments uc (cost=0.00..4464.19 rows=3005 width=8)
Filter: (remind_user_id = 5388)
-> Hash (cost=5930.98..5930.98 rows=146927 width=10)
-> Seq Scan on tbl_comments c (cost=0.00..5930.98 rows=146927 width=10)
Filter: is_system
-> Hash (cost=4937.62..4937.62 rows=25 width=10)
-> Subquery Scan on sub (cost=4933.40..4937.62 rows=25 width=10)
-> Finalize GroupAggregate (cost=4933.40..4937.37 rows=25 width=10)
Group Key: uc_1.object_type
-> Gather Merge (cost=4933.40..4936.99 rows=25 width=10)
Workers Planned: 1
-> Partial GroupAggregate (cost=3933.39..3934.17 rows=25 width=10)
Group Key: uc_1.object_type
-> Sort (cost=3933.39..3933.57 rows=71 width=2)
Sort Key: uc_1.object_type
-> Nested Loop (cost=0.42..3931.21 rows=71 width=2)
-> Parallel Seq Scan on tbl_unread_comments uc_1 (cost=0.00..3246.52 rows=87 width=6)
Filter: ((NOT is_read) AND (remind_user_id = 5388))
-> Index Scan using tbl_comments_pkey on tbl_comments c_1 (cost=0.42..7.87 rows=1 width=4)
Index Cond: (id = uc_1.comment_id)
Filter: is_system