Module datafusion_expr::window_frame

Window frame module

The frame-spec determines which output rows are read by an aggregate window function. The frame-spec consists of four parts:

• A frame type - either ROWS, RANGE or GROUPS,
• A starting frame boundary,
• An ending frame boundary,
• An EXCLUDE clause.

Structs

• WindowFrame
  The frame specification determines which output rows are read by an aggregate window function. The ending frame boundary can be omitted if the BETWEEN and AND keywords that surround the starting frame boundary are also omitted, in which case the ending frame boundary defaults to CURRENT ROW.

Enums

• WindowFrameBound
  There are five ways to describe starting and ending frame boundaries:
• WindowFrameUnits
  There are three frame types: ROWS, GROUPS, and RANGE. The frame type determines how the starting and ending boundaries of the frame are measured.

Functions

• check_window_frame
  Checks if given window frame is valid. In particular, if the frame is RANGE with offset PRECEDING/FOLLOWING, it must have exactly one ORDER BY column.
• convert_frame_bound_to_scalar_value
• regularize_window_order_by
  Regularizes ORDER BY clause for window definition for implicit corner cases.