Window Unary Logical Operator
Window
is a unary logical operator that is created for:
-
a collection of named expressions (for windows)
-
a collection of expressions (for partitions)
-
a collection of
SortOrder
(for sorting) and a child logical plan.
The output
(collection of Attributes) is the child’s attributes and the window’s.
Window
logical plan is a subject of pruning unnecessary window expressions in ColumnPruning rule and pushing filter operators in PushDownPredicate rule.