public function table_exists($table) {
		# we can't use placeholder for table name
		if (!preg_match('!^[0-9a-z_]+$!i', $table))
			return false;
		self::$logger->deactivate();
		try {
			$this->query(sprintf("SELECT 1 FROM %s LIMIT 1", $table));
			self::$logger->activate();
			return true;
		} catch(SQLError $e) {
			self::$logger->activate();
			return false;
		}
	}