Autocomplete with filtering serverside

[Coty]

Hey there, I am reviewing the functionality of the AutoComplete and have a question on how the filtering works for the remote datasource.  I want to use it to pull a list of contacts.  Kendo Example: http://demos.telerik.com/kendo-ui/autocomplete/serverfiltering

However I don't understand how the remote datasource connection works.  All of the examples point to a service that pull a list but I don't see where they send the search filter criteria to the server?

For example I would expect the service call to be something like: \Controller\Action\myFilterString   (Or sending data in the body of an ajax call)

So that leads me to believe that the autocomplete pulls the entire list, and then does all filtering client side.  Which is probably great in most cases, but when the dataset gets very large does it hurt performance or use too much memory?   Does anyone have any experience with larger datasets?

In my case my User list is currently 3500 records, but I expect that to probably double in about a year.

If anyone wants to share there thoughts on best practices with large datasets, please chime in.  (IE when is a large dataset considered TOO large to pull the entire list?)

Thank You!

[Coty]

Hey there I actually did figure this out now, didn't realize the autocomplete attached query string values to the URL.  I just grab the querystring value on the server side and do my custom filter.  thanks.