QUERY PLAN
Aggregate (cost=4716.23..4716.24 rows=1 width=8)
-> Sort (cost=4665.59..4674.03 rows=3376 width=2971)
Sort Key: c.created_at DESC
-> Seq Scan on tbl_contacts c (cost=0.00..138.24 rows=3376 width=2971)
Filter: (client_id IS NOT NULL)