Confluent doesn't understand the ANSI SQL standard. Support for aggregating over windows with standard syntax goes back to SQL:99, so it's been around for 18 years. Any company playing in the SQL space should make a point of understanding the standard.
SQLstream could not agree with you more that an up-front explanation of SQL compatibility level is necessary to evaluate a product. SQLstream Blaze is SQL:2011 compliant.
There is a good explanation of ANSI SQL standard windowing at http://sqlstream.com/docs/conc_applicationdesign.html?zoom_h.... The document describes both tumbling and rolling windows as well as how they are achieved with standard syntax.
SQLstream could not agree with you more that an up-front explanation of SQL compatibility level is necessary to evaluate a product. SQLstream Blaze is SQL:2011 compliant.