QUERY PLAN
GroupAggregate (cost=332.53..333.15 rows=35 width=12)
Group Key: client_id
-> Sort (cost=332.53..332.62 rows=36 width=8)
Sort Key: client_id
-> Seq Scan on tbl_cases (cost=0.00..331.60 rows=36 width=8)
Filter: (client_id = ANY ('{2181,112,1186,334,1876,161,1250,473}'::integer[]))