PLV8 example - accumulator

benchmark_v8.sql

--
-- Benchmark PLV8
--

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

-- DROP FUNCTION IF EXISTS fillaccumulator();
CREATE OR REPLACE FUNCTION fillaccumulator () RETURNS void AS $$
    var rows = plv8.execute( "SELECT count(*), SUM(new_value) FROM accumulator" );
    var rand = Math.floor((Math.random() * 100) + 1)
    // plv8.elog(NOTICE, rand);
    plv8.execute("INSERT INTO accumulator (new_value, sum_previous) VALUES($1, $2)", [1, rows[0].sum]);
$$
LANGUAGE plv8;

SELECT fillaccumulator();

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

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

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