Module windows

Physical expressions for window functions

Structs

• BoundedWindowAggExec
  Window execution plan
• BuiltInWindowExpr
  A window expr that takes the form of a BuiltInWindowFunctionExpr.
• PlainAggregateWindowExpr
  A window expr that takes the form of an aggregate function.
• WindowAggExec
  Window execution plan

Traits

• WindowExpr
  Common trait for window function implementations

Functions

• create_window_expr
  Create a physical expression for window function
• get_best_fitting_window
  Constructs the best-fitting windowing operator (a WindowAggExec or a BoundedWindowExec) for the given input according to the specifications of window_exprs and physical_partition_keys. Here, best-fitting means not requiring additional sorting and/or partitioning for the given input.
• get_ordered_partition_by_indices
  This function calculates the indices such that when partition by expressions reordered with the indices resulting expressions define a preset for existing ordering. For instance, if input is ordered by a, b, c and PARTITION BY b, a is used, this vector will be [1, 0]. It means that when we iterate b, a columns with the order [1, 0] resulting vector (a, b) is a preset of the existing ordering (a, b, c).
• get_window_mode
  Compares physical ordering (output ordering of the input operator) with partitionby_exprs and orderby_keys to decide whether existing ordering is sufficient to run the current window operator.
• schema_add_window_field
  Build field from window function and add it into schema