autocomplete assistance.

Hello,

I am hoping to create an autocomplete feature for building search dataset.

I plan to use this link (http://www.simonwhatley.co.uk/examples/autocomplete/mootools/)

But I noticed that the dataset comes from a json file, which I am not familiar with or a huge array. While I would like to keep the redundancy of data reduced, would it be possible to query my database to look for the names?

I had seen this link (http://www.ajaxupdates.com/ajax-script-autocomplete-using-mootools/) and it had mentioned php to make a database query, but I am also under the impression that it also uses json file.

I have somewhat of an idea of what is happening, but a little clarification would be great.

Thanks