set enable_indexonlyscan = off;
set parallel_setup_cost = 0;
set parallel_tuple_cost = 0;
set min_parallel_table_scan_size = 0;
set max_parallel_workers_per_gather = 2;

prepare ab_q5 (int, int, int) as
select avg(a) from ab where a in($1,$2,$3) and b < 4;

execute ab_q5 (1, 2, 3);
execute ab_q5 (1, 2, 3);
execute ab_q5 (1, 2, 3);
execute ab_q5 (1, 2, 3);
execute ab_q5 (1, 2, 3);

explain (analyze, costs off, summary off, timing off) execute ab_q5 (2, 3, 3);