I really wish frameworks offering SQL would upfront say what level of SQL compatibility they have, is it SQL 2011, is it Postgres etc...
Anyways, if anyone's wondering, here's the Github page. [1]
Also from FAQ [2]:
Is KSQL fully compliant to ANSI SQL?
KSQL is a dialect inspired by ANSI SQL. It has some differences because it is geared at processing streaming data. For example, ANSI SQL has no notion of “windowing” for use cases such as performing aggregations on data grouped into 5-minute windows, which is a commonly required functionality in the streaming world.
I'm assuming that most "SQL" implementations in distributed systems don't actually follow the SQL standard. They just offer a SQL like syntax to solve common problems. I could be wrong, but that's the impression I get working with tools like Cassandra/Spark.
ANSI SQL should be extended to standardize streaming syntax. There are certainly enough vendors that have it now... for example, sqlstream.com. It's too bad that SQL:2011 didn't get these features since it had a lot of temporal-related extensions.
Flink's SQL implementation actually follows ANSI SQL - which I think is very important.
There is a way of interpreting streams and tables to make ANSI SQL meaningful in the presence of streams, which we follow [1].
The big advantage is (besides not having to learn another syntax and retaining compatibility with SQL tools and dashboards) that this seamlessly handles the batch (bounded/static input) and streaming (unbounded/continuous) use cases with literally the same SQL statement.
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.
Anyways, if anyone's wondering, here's the Github page. [1]
Also from FAQ [2]:
Is KSQL fully compliant to ANSI SQL?
KSQL is a dialect inspired by ANSI SQL. It has some differences because it is geared at processing streaming data. For example, ANSI SQL has no notion of “windowing” for use cases such as performing aggregations on data grouped into 5-minute windows, which is a commonly required functionality in the streaming world.
[1] https://github.com/confluentinc/ksql/blob/0.1.x/docs/syntax-...
[2] https://github.com/confluentinc/ksql/blob/0.1.x/docs/faq.md#...