What is the fastest jQuery v1.4.4 Ajax content respond way by server-side?

What is the fastest jQuery v1.4.4 Ajax content respon开发者_运维问答d way by server-side? I use PHP and MySQL.

Do I have to convert MySQL data to JSON or XML format? Or is there simpler way to have fastest Ajax respond by MySQL?

I might to use jQuery Address State for it - https://github.com/asual/jquery-address, but seems it has to load-in a full html file just for to update small peaces of content data.

Preparing JSON would be a bit faster, then XML, and it will be smaller and faster sent to client.

But really, I would focus on MySQL performance in your case. Selecting data will be times and times slower than sending a result via ajax.