Prioritizing Windows
Because windows are defined according to a time scale, only one window is active at any point in time. Suppose that you have defined two windows as follows:
Window W1 starts at 7 A.M. and ends at 9 P.M.
Window W2 starts at 7 P.M. and ends at 7 A.M.
These two windows overlap between 7 P.M. and 9 P.M. During that time, which window will be active?
The Scheduler resolves this situation according to the priority you have assigned to each window. You specify the priority in the window_priority parameter of the CREATE_WINDOW procedure. The only two possible values are “low” (the default) and “high.” For example:
window_priority => 'high'
When windows overlap, the one with the “high” priority will be activated. If two windows with the same priority overlap, then the window that is going to end sooner is given precedence, and the other window waits.