QUERY PLAN
Sort (cost=23677.30..23679.05 rows=700 width=18)
Sort Key: c.object_type
-> HashAggregate (cost=23637.22..23644.22 rows=700 width=18)
Group Key: c.object_type, sub.unreadcount
-> Hash Left Join (cost=17804.85..23467.46 rows=33952 width=10)
Hash Cond: ((c.object_type)::text = (sub.object_type)::text)
-> Hash Right Join (cost=8496.01..14056.00 rows=33952 width=2)
Hash Cond: (uc.comment_id = c.id)
Filter: ((uc.remind_user_id = 1001) OR (c.created_by = 1001))
-> Seq Scan on tbl_unread_comments uc (cost=0.00..4470.11 rows=35383 width=8)
Filter: (remind_user_id = 1001)
-> Hash (cost=5938.18..5938.18 rows=147106 width=10)
-> Seq Scan on tbl_comments c (cost=0.00..5938.18 rows=147106 width=10)
Filter: is_system
-> Hash (cost=9308.54..9308.54 rows=25 width=10)
-> Subquery Scan on sub (cost=9298.62..9308.54 rows=25 width=10)
-> Finalize GroupAggregate (cost=9298.62..9308.29 rows=25 width=10)
Group Key: uc_1.object_type
-> Gather Merge (cost=9298.62..9307.91 rows=25 width=10)
Workers Planned: 1
-> Partial GroupAggregate (cost=8298.61..8305.09 rows=25 width=10)
Group Key: uc_1.object_type
-> Sort (cost=8298.61..8300.68 rows=831 width=2)
Sort Key: uc_1.object_type
-> Nested Loop (cost=0.42..8258.31 rows=831 width=2)
-> Parallel Seq Scan on tbl_unread_comments uc_1 (cost=0.00..3250.83 rows=1024 width=6)
Filter: ((NOT is_read) AND (remind_user_id = 1001))
-> Index Scan using tbl_comments_pkey on tbl_comments c_1 (cost=0.42..4.89 rows=1 width=4)
Index Cond: (id = uc_1.comment_id)
Filter: is_system