New Features in Release 20.2

Generic ORDER BY and GROUP BY

In previous releases, ORDER BY and GROUP BY were possible only if there was an index that sorted the rows by the ORDER BY/GROUP BY expressions. Furthermore, it was not possible for queries to include both ORDER BY and GROUP BY. These restrictions are lifted in this release. Note that generic ORDER BY and GROUP BY may consume a lot of driver memory, because of the need to materialize the full query result in driver memory.

SELECT DISTINCT

The DISTINCT keyword is now supported in the SELECT clause. If present, duplicate results will be removed from query result set. As with generic ORDER BY and GROUP BY, SELECT DISTINCT needs to cache the full result set in driver memory.

TTL in Streams API and Multi-Region Tables

Added support for Time to Live (TTL) in the Streams API and in Multi-Region tables. The Rows supplied by the Streams API to subscribers will include the TTL expiration time for the operation from source store. For Multi-Region tables, the TTL expiration time of each row is replicated to other regions, and thus a row in Multi-Region table in any region will expire at the expiration time replicated from the region where and when operation is made.