Function computeValidFrames

bolt/exec/Window.cpp:716–740

Frame end points are always expected to go from frameStart to frameEnd rows in increasing row numbers in the partition. k rows/range frames could potentially violate this. This function identifies the rows that violate the framing requirements and sets bits in the validFrames SelectivityVector for usage in the WindowFunction subsequently.

// and sets bits in the validFrames SelectivityVector for usage in the
// WindowFunction subsequently.
void computeValidFrames(
    vector_size_t lastRow,
    vector_size_t numRows,
    vector_size_t* rawFrameStarts,
    vector_size_t* rawFrameEnds,
    SelectivityVector& validFrames) {
  auto frameStart = 0;
  auto frameEnd = 0;

  for (auto i = 0; i < numRows; i++) {
    frameStart = rawFrameStarts[i];
    frameEnd = rawFrameEnds[i];
    // All valid frames require frameStart <= frameEnd to define the frame
    // rows. Also, frameEnd >= 0, so that the frameEnd doesn't fall before the
    // partition. And frameStart <= lastRow so that the frameStart doesn't
    // fall after the partition rows.
    if (frameStart <= frameEnd && frameEnd >= 0 && frameStart <= lastRow) {
      rawFrameStarts[i] = std::max(frameStart, 0);
      rawFrameEnds[i] = std::min(frameEnd, lastRow);
    } else {
      validFrames.setValid(i, false);
    }
  }
  validFrames.updateBounds();
}

}; // namespace