public function getPool()
    {
        if (!isset($this->_pool)) {
            $poolConfig = [
                'loop' => $this->loop,
                'clientConfig' => [
                    ['class' => pgConnection::class],
                    [
                        $this->connectionParams,
                        $this->loop,
                        $this->connector
                    ]
                ]
            ];
            $poolConfig = ArrayHelper::merge($this->poolConfigDefault, $this->poolConfig, $poolConfig);
            $this->_pool = new Pool($poolConfig);
        }
        return $this->_pool;
    }