QUERY PLAN
Sort (cost=28016.89..28023.00 rows=2444 width=18)
Sort Key: c.object_type
-> HashAggregate (cost=27854.91..27879.35 rows=2444 width=18)
Group Key: c.object_type, sub.unreadcount
-> Hash Left Join (cost=20991.54..27645.58 rows=41866 width=10)
Hash Cond: ((c.object_type)::text = (sub.object_type)::text)
-> Hash Right Join (cost=10067.92..16603.11 rows=41866 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..5232.30 rows=40338 width=8)
Filter: (remind_user_id = 1001)
-> Hash (cost=6933.05..6933.05 rows=180310 width=10)
-> Seq Scan on tbl_comments c (cost=0.00..6933.05 rows=180310 width=10)
Filter: is_system
-> Hash (cost=10923.03..10923.03 rows=47 width=11)
-> Subquery Scan on sub (cost=10908.21..10923.03 rows=47 width=11)
-> Finalize GroupAggregate (cost=10908.21..10922.56 rows=47 width=11)
Group Key: uc_1.object_type
-> Gather Merge (cost=10908.21..10921.85 rows=47 width=11)
Workers Planned: 1
-> Partial GroupAggregate (cost=9908.20..9916.55 rows=47 width=11)
Group Key: uc_1.object_type
-> Sort (cost=9908.20..9910.83 rows=1051 width=3)
Sort Key: uc_1.object_type
-> Nested Loop (cost=0.42..9855.45 rows=1051 width=3)
-> Parallel Seq Scan on tbl_unread_comments uc_1 (cost=0.00..3808.29 rows=1254 width=7)
Filter: ((NOT is_read) AND (remind_user_id = 1001))
-> Index Scan using tbl_comments_pkey on tbl_comments c_1 (cost=0.42..4.82 rows=1 width=4)
Index Cond: (id = uc_1.comment_id)
Filter: is_system