Ajax使浏览器挂起（PHP ZEND）

I am trying to get the data and auto-populate dropdown from the data in DB. For this i am doing an ajax call with every character added.

So as user types, with every character typed , ajax calls goes to the server and returns results.

Now there is lot of data on server side and while getting back browser hangs .

what can i do to curb it.

var Url = '/abc/def/ghi';
    $("#id").select2({
            placeholder: "Select the Broker",
            minimumInputLength: 1,
            ajax: {
                url: Url,
                dataType: 'json',
                data: function (term, page) {
                    return {
                        term: term, // search term
                        page_limit: 10,
                    };
                },
                results: function (data, page) {
                    return {results: data};
                },
                allowClear: false
            }
        });

Is there any possible way i can make ajax calls in a better way.