If you are connected to a data dictionary, and you have designated a default index for a table, that index will automatically be used when you open that table using an AdsTable. If you do not have a default index, or want to switch to some other index, you set the IndexName property of the AdsTable to the name of the index you want to use. This is demonstrated in the following code segment, which is associated with the Select Invoice No Index button (shown in Figure 15-2):

procedure TForm1.SetIndexBtnClick(Sender: TObject);
begin
 if (AdsTable1.TableName <> 'INVOICE') and
   (AdsTable1.Active) then
   AdsTable1.Close;
 AdsTable1.IndexName := 'Invoice No';
end;