On contexts and separation of concerns - the case of "On Off Windows"

2008-12-10T17:26:00.006+02:00

The window in the picture cannot be openned or closed without some fixing, which is typical to some of the event processing language that support in fixed window. I have been quite amused in the last couple of days to read the discussion in the CEP-Interest Group on Yahoo!, started by
a query posted by Pedro Bizarro.
If you do not subscribe on this group I am copying Pedro's query:

Hi there,

A company contacted me to solve a query puzzle that they have. They
are reading incoming tuples and want to select all tuples that are
between two tuples. For example, assume that I want all tuples between
the first tuple with PARAM1=2 and the first tuple after this one with
PARAM2=0. This would select all tuples with time between 3 and 8 in
the example below.

TIME | PARAM1 | PARAM2
1 1 0
2 1 1
<span style="color: rgb(255, 102, 0);">3 2 2