QUERY PLAN
Finalize Aggregate (cost=9528.85..9528.86 rows=1 width=8)
-> Gather (cost=9528.73..9528.84 rows=1 width=8)
Workers Planned: 1
-> Partial Aggregate (cost=8528.73..8528.74 rows=1 width=8)
-> Nested Loop (cost=0.42..8526.52 rows=884 width=0)
-> Parallel Seq Scan on tbl_unread_comments uc (cost=0.00..3322.37 rows=1072 width=4)
Filter: ((NOT is_read) AND (remind_user_id = 1001))
-> Index Scan using tbl_comments_pkey on tbl_comments c (cost=0.42..4.85 rows=1 width=4)
Index Cond: (id = uc.comment_id)
Filter: is_system