#!/bin/bash

dbname=postgres
rows=1000000
secs=10
ntests=3

psql -c "create extension if not exists pg_prewarm;" $dbname
psql -c "drop table if exists part_test;" $dbname
psql -c "create table part_test (a int not null);" $dbname
psql -c "insert into part_test select g.s from generate_series(1,$rows) g(s);" $dbname
psql -c "vacuum freeze analyze part_test;" $dbname
psql -c "select pg_prewarm('part_test');" $dbname
psql -c "alter system set work_mem = '256MB';" $dbname
psql -c "alter system set jit = 0;" $dbname
psql -c "select pg_reload_conf();" $dbname

for c in 1 10 100 1000 10000 100000 1000000
do
	echo "SELECT a,count(*) OVER (PARTITION BY a / $c) FROM part_test OFFSET $rows" > bench.sql
	echo "Testing with $(($rows / $c)) partitions"
	for i in $(seq 1 $ntests)
	do
		pgbench -n -f bench.sql -M prepared -T $secs $dbname | grep latency
	done
done