This Calcite release makes it possible to exploit physical properties
of relational expressions to produce more efficient plans, introducing
collation and distribution as traits,
Exchange relational operator,
and several new forms of metadata.
We add experimental support for streaming SQL.
This release drops support for JDK 1.6; Calcite now requires 1.7 or later.
We have introduced static
create methods for many sub-classes of
RelNode. We strongly suggest that you use these rather than
calling constructors directly.