The two most important factors affecting performance of your ASTA client application are bandwidth and your application design. It is important to follow the client/server prime directive: Fetch ONLY what you need WHEN you need it.
This means that:
Select * from Customers
Select Last, First, ID from Customers Where Age > 30
If you come from a file server background, then you should think about moving from a procedural, navigational model to an SQL result set oriented design.
The "appearance" of great speed and responsiveness can be achieved by limiting the amount of data requested from ASTA servers, and the number of requests made to the server. Client/server round trips are costly