>>> What we are talking about here is *defining* a window >>> frame. >> Well, we are defining a "reduced" window frame within a (full) window >> frame. A "reduced" window frame is calculated each time when a window >> function is called. > > > Why? It should only be recalculated when the current row changes and > we need a new frame. The reduced window frame *is* the window frame > for all functions over that window.
We already recalculate a frame each time a row is processed even without RPR. See ExecWindowAgg. Also RPR always requires a frame option ROWS BETWEEN CURRENT ROW, which means the frame head is changed each time current row position changes. > I strongly disagree with this. Window function do not need to know > how the frame is defined, and indeed they should not. We already break the rule by defining *support functions. See windowfuncs.c. > WinGetFuncArgInFrame should answer yes or no and the window function > just works on that. Otherwise we will get extension (and possibly even > core) functions that don't handle the frame properly. Maybe I can move row_is_in_reduced_frame into WinGetFuncArgInFrame just for convenience. Best reagards, -- Tatsuo Ishii SRA OSS LLC English: http://www.sraoss.co.jp/index_en/ Japanese:http://www.sraoss.co.jp
