If like me you got PowerBuilder 5 and saw dot notation access to datawindows and thought that looks good, beware.

It is quite a bit slower to do
  this.Object.customer_name[ll_row]
than
  this.GetItemString(ll_row,"customer_name")

This is highlighted it you time a loop of datawindow access.

Dot notation has also been prone to causing GPF's especially when accessing numbers and is limited to 32767.
I think these problems have been solved in Popwerbuilder 6
However dot notation is very good at setting arrays. The following code is far easier than looping though the datawindow.

String ls_customer_name[]
ls_customer_name = this.Object.customer_name.Primary

Note: The performance issues may have been solved with issues 6 and 7 of Powerbuilder.