QUERY PLAN
GroupAggregate (cost=100.49..100.64 rows=9 width=12)
Group Key: case_id
-> Sort (cost=100.49..100.51 rows=9 width=4)
Sort Key: case_id
-> Seq Scan on tbl_pre_sales (cost=0.00..100.34 rows=9 width=4)
Filter: (case_id = ANY ('{8252,8259,8250,8258,8255,8253,8251,8245,8248}'::integer[]))