QUERY PLAN
Group (cost=18356.54..18360.49 rows=527 width=18)
Group Key: c.object_type, sub.unreadcount
-> Sort (cost=18356.54..18357.86 rows=527 width=10)
Sort Key: c.object_type, sub.unreadcount
-> Hash Left Join (cost=14202.50..18332.72 rows=527 width=10)
Hash Cond: ((c.object_type)::text = (sub.object_type)::text)
-> Hash Right Join (cost=9748.96..13877.66 rows=527 width=2)
Hash Cond: (uc.comment_id = c.id)
Filter: ((uc.remind_user_id = 1000) OR (c.created_by = 1000))
-> Gather (cost=1000.00..4373.41 rows=489 width=8)
Workers Planned: 1
-> Parallel Seq Scan on tbl_unread_comments uc (cost=0.00..3324.51 rows=288 width=8)
Filter: (remind_user_id = 1000)
-> Hash (cost=6080.26..6080.26 rows=153496 width=10)
-> Seq Scan on tbl_comments c (cost=0.00..6080.26 rows=153496 width=10)
Filter: is_system
-> Hash (cost=4453.30..4453.30 rows=19 width=10)
-> Subquery Scan on sub (cost=4451.30..4453.30 rows=19 width=10)
-> Finalize GroupAggregate (cost=4451.30..4453.11 rows=19 width=10)
Group Key: uc_1.object_type
-> Gather Merge (cost=4451.30..4452.86 rows=12 width=10)
Workers Planned: 1
-> Partial GroupAggregate (cost=3451.29..3451.50 rows=12 width=10)
Group Key: uc_1.object_type
-> Sort (cost=3451.29..3451.32 rows=12 width=2)
Sort Key: uc_1.object_type
-> Nested Loop (cost=0.42..3451.08 rows=12 width=2)
-> Parallel Seq Scan on tbl_unread_comments uc_1 (cost=0.00..3324.51 rows=15 width=6)
Filter: ((NOT is_read) AND (remind_user_id = 1000))
-> 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