Temporal support in SQL:2011

[Julian Hyde <jh...@apache.org>]

(Apologies for the cross-post. It seemed to be of interest to both lists.)

The latest incarnation of the SQL standard, SQL:2011, adds temporal
support. Time is an important concept in streams, so my hunch is that
temporal database features will also be useful in streaming SQL.

While we’re thinking about streaming SQL for Samza, it’s worth taking a
look at what’s in the standard. We don’t need to support every feature in
the standard (heaven forbid!) but if we are going to do a feature, we’d be
well advised to do it the standard way.

For example, they have temporal predicates (CONTAINS, OVERLAPS, etc.) based
on Allen’s interval relations[1].

Wikipedia has a nice summary[2].

Julian

[1] http://en.wikipedia.org/wiki/Allen%27s_interval_algebra#Relations
<http://en.wikipedia.org/wiki/Allen's_interval_algebra#Relations>

[2] http://en.wikipedia.org/wiki/SQL:2011#New_features