#!/usr/bin/perl
use v5.28;
use warnings;

use Time::HiRes qw(clock_gettime CLOCK_MONOTONIC);

my $t0 = clock_gettime(CLOCK_MONOTONIC);

use DBI;

for my $rep (1 .. 2) {
    my $t1 = clock_gettime(CLOCK_MONOTONIC);

    my $dbh = DBI->connect("dbi:Pg:", "");

    my $t2 = clock_gettime(CLOCK_MONOTONIC);
    my $result = $dbh->selectall_arrayref("select current_timestamp");
    my $t3 = clock_gettime(CLOCK_MONOTONIC);
    $dbh->disconnect();
    my $t4 = clock_gettime(CLOCK_MONOTONIC);

    say $t2 - $t1, " connect $rep";
    say $t4 - $t1, " session $rep";
}