GROUP BY PERIOD: form groups without non-temporal attributes
Created by: Piiit
Syntax:
GROUP BY PERIOD WITH (column_name [, column_name] ) [expression [, ...]]
Single column_name means range typed boundaries, i.e. t
, whereas two column_name fields mean separated boundaries, i.e., ts
and te
. The difference to the old syntax as shown in issue #34 is that the expression
is now optional. This means that we can now form groups without any non-temporal attributes.