The default perspective is indicated in the
Select Perspective dialog (accessible via the Window > Open Perspective
> Other... menu). The pre-defined default perspective is indicated by the
word default in brackets following the perspective name, for example, Resource
(default).
To change the default perspective:
General > Perspectives
preference page.
Select the perspective that you want to define as the
default from the list of available perspectives, and click Make Default.
The default indicator moves to the perspective that you selected.