Jquery UI Autocomplete to search through multiple XML elements

I have a JQuery UI autocomplete widget that is currently looking at a database of contacts. Users can search by contact name, email, company etc. However the query is a little complex and can lag occasionally, so I am looking to switch it to a dynamically XML file for speed, yet I want to keep to ability to search on multiple fields. I cant not figure out how to do this currently, could anyone point me开发者_JAVA技巧 in the right direction of how to match the term to multiple XML fields? Thankyou.

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This question of 2010 looks similar: Jquery ui autocomplete - multiple sources I would suggest combining the first answer with the second answer. As far as I remember when I was working with the JQuery autocomplete I found it required JavaScript Object Notation in order to function, not XML.

Hope this helps :)