Re: memory leak under heavy load?

On 11/29/05, hubert depesz lubaczewski <depesz@gmail.com> wrote:
now i'm nearly positive it's a bug.

i created database in this way:
CREATE DATABASE leak;
\c leak
CREATE TABLE users (id serial PRIMARY KEY, username TEXT NOT NULL DEFAULT '', password TEXT);
then made a list of "usernames": from "aaaa" to "czzz" with probability 97% - 3% are missing.
and then i COPY'ied this list into users.

then:
CREATE UNIQUE INDEX xxx on users (username);
vacuum verbose analyze;

after all of this i run this script:
#!/usr/bin/perl
use strict;
use DBI;

my $dbh = DBI->connect("dbi:Pg:dbname=leak", "pgdba", "", {"AutoCommit" => 0,
    "RaiseError" => 0, "PrintError" => 0}) or die "cannot connect\n";

for (1..1000) {
    my $i = 0;
    my $q = "zzz";
    while (1) {
        $dbh->rollback();
        $dbh->do("INSERT INTO users (username) VALUES ('$q')");
        $dbh->commit();
        $q++;
        last if $q eq 'fzzz';
        $i++;
        if (0 == $i % 1000) {
            system("ps uxf");
        }
    }
    print "one iteration done\n";
    <>;
}
$dbh->disconnect();


technically - i think that after first "iteration" memory usage should not inreate. but it does.
it does in small amounts, but still does.
can anybody test/confirm the problem?

depesz