framework/db/mysql/QueryBuilder.php
private function supportsFractionalSeconds()
    {
        $version = $this->db->getSlavePdo()->getAttribute(\PDO::ATTR_SERVER_VERSION);
        return version_compare($version, '5.6.4', '>=');
    }
private function supportsFractionalSeconds()
    {
        $version = $this->db->getSlavePdo()->getAttribute(\PDO::ATTR_SERVER_VERSION);
        return version_compare($version, '5.6.4', '>=');
    }
Checks the ability to use fractional seconds.

@return bool
@see https://dev.mysql.com/doc/refman/5.6/en/fractional-seconds.html