--- perl_lib/IRStats/DatabaseInterface.pm	2012-01-23 14:38:33.000000000 +0000
+++ perl_lib/IRStats/DatabaseInterface.pm	2012-11-29 16:23:29.000000000 +0000
@@ -48,6 +48,10 @@
 		$id_column,
 	);
 
+	# avoid memory cycle persisting database connection
+	Scalar::Util::weaken( $self->{session} ) if defined &Scalar::Util::weaken;
+
 	@{$self->{sets}} = ('eprint',$conf->set_ids);
 
 	return $self;