MySQL 8.4.3
Source Code Documentation
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Collects evaluation requirements from a window function, used by Item_sum::check_wf_semantics and its overrides. More...
#include <window.h>
Public Member Functions | |
Window_evaluation_requirements () | |
Public Attributes | |
bool | needs_buffer |
Set to true if window function requires row buffering. More... | |
bool | needs_peerset |
Set to true if we need peerset for evaluation (e.g. More... | |
bool | needs_last_peer_in_frame |
Set to true if we need last peer for evaluation within a frame (e.g. More... | |
bool | opt_first_row |
Set to true if we need FIRST_VALUE or optimized MIN/MAX. More... | |
bool | opt_last_row |
Set to true if we need LAST_VALUE or optimized MIN/MAX. More... | |
Window::st_offset | opt_nth_row |
Used if we have NTH_VALUE. More... | |
Window::st_ll_offset | opt_ll_row |
Used if we have LEAD or LAG. More... | |
bool | row_optimizable |
Set to true if we can compute a sliding window by a combination of undoing the contribution of rows going out of the frame and adding the contribution of rows coming into the frame. More... | |
bool | range_optimizable |
Similar to row_optimizable but for RANGE frame bounds unit. More... | |
Collects evaluation requirements from a window function, used by Item_sum::check_wf_semantics and its overrides.
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inline |
bool Window_evaluation_requirements::needs_buffer |
Set to true if window function requires row buffering.
bool Window_evaluation_requirements::needs_last_peer_in_frame |
Set to true if we need last peer for evaluation within a frame (e.g.
JSON_OBJECTAGG)
bool Window_evaluation_requirements::needs_peerset |
Set to true if we need peerset for evaluation (e.g.
CUME_DIST)
bool Window_evaluation_requirements::opt_first_row |
Set to true if we need FIRST_VALUE or optimized MIN/MAX.
bool Window_evaluation_requirements::opt_last_row |
Set to true if we need LAST_VALUE or optimized MIN/MAX.
Window::st_ll_offset Window_evaluation_requirements::opt_ll_row |
Used if we have LEAD or LAG.
Window::st_offset Window_evaluation_requirements::opt_nth_row |
Used if we have NTH_VALUE.
bool Window_evaluation_requirements::range_optimizable |
Similar to row_optimizable but for RANGE frame bounds unit.
bool Window_evaluation_requirements::row_optimizable |
Set to true if we can compute a sliding window by a combination of undoing the contribution of rows going out of the frame and adding the contribution of rows coming into the frame.
For example, SUM and AVG allows this, but MAX/MIN do not. Only applicable if the frame has ROW bounds unit.