I want to inquire that fetching data using jquery auto complete in asp.net pages, is expensive or fetching data by sqlreader , by performance pointview. which is best way.
You need a SqlDataReader (or simialr) if you are using the AutoComplete control.
I think when using jquery, json (java) page "postback" not happening. furthermore I will celebrate the above question that when using alone datareader for data fetching in page is best way or using jquery-json with autocomplete.
but there is more than one choice I found in asp.net, auto complete with scriptmanager or auto complete with jquery json , with webservice and without webservice.
so I feel its confusing, we should identity which is best way performance point view.
I think you need to understand the basics of how all of this works before worrying about possible performance issues. You cannot use jQuery to get data from a database. You must use a data access technology. Any technology you use will use a DataReader in
the background. But a forum post is not the best way to clarify all of your misunderstandings.
But if you are so concerned about performance, create your own tests using all of the approaches you seem to have identified and perform your own measurements. You might learn how all this works along the way.