--
-- Benchmark PLLUA
--

DROP TABLE accumulator;
CREATE TABLE accumulator (id BIGSERIAL PRIMARY KEY, new_value INT, sum_previous INT);

CREATE OR REPLACE FUNCTION fillaccumulator() RETURNS void AS $$
    local query = server.execute('SELECT count(*), SUM(new_value) FROM accumulator', true, 1) -- read-only, only 1
    local random = math.random
    local p = server.prepare("INSERT INTO accumulator (new_value, sum_previous) VALUES($1, $2)", {"int4", "int4"})
    p:execute{math.random(0, 99), query[1].sum} -- insert values
$$ LANGUAGE pllua;

-- SELECT fillaccumulator();

CREATE OR REPLACE FUNCTION plbench(query text, n int) returns float as $$
DECLARE
    t0 timestamp with time zone;
    e float;
BEGIN
    t0 := clock_timestamp();
    for i in 1 .. n loop
        execute query;
    end loop;
    e = extract(microseconds from clock_timestamp()) - extract(microseconds from t0);
    return e / 1000000;
END;
$$ language plpgsql;

SELECT plbench('SELECT fillaccumulator()', 10000);

SELECT count(*), SUM(new_value) FROM accumulator;