The CCL language (Aleri/Coral8) has some notion of window with keep policies that control the type of the window.

CCL example for Window and keep policies.

Windows are like streams, but store records
CREATE WINDOW Book_w SCHEMA Book_t KEEP ALL;
INSERT INTO Book_w
  SELECT * FROM Book_s;

Sample of KEEP policies (there are others):
KEEP LAST PER Id
KEEP 3 MINUTES
KEEP EVERY 3 MINUTES
KEEP UNTIL (”MON 17:00:00”)
KEEP 10 ROWS
KEEP LAST ROW
KEEP 10 ROWS PER Symbol

Note that the notion of CCL window has many of the functions of context we have discussed before, including several types of temporal contexts, and a composed context by segmentation.

The next figure shows an example definition of a temporal segmentation using AMiT





 
Note: AMiT is not available through this website.
In this example, there is a definition of event initiator in the highest frame, followed by definition of grouping key (segmentation context) and the terminator as an offset of 2:00 minutes. Various other languages support some of the context options in various forms.