QUERY PLAN
GroupAggregate (cost=352.91..353.68 rows=43 width=12)
Group Key: client_id
-> Sort (cost=352.91..353.02 rows=45 width=8)
Sort Key: client_id
-> Seq Scan on tbl_cases (cost=0.00..351.67 rows=45 width=8)
Filter: (client_id = ANY ('{1661,3375,2128,2492,3360,3361,3329,2547,3365,2158}'::integer[]))