Method estimateBytesPerRow

bolt/exec/TableScan.cpp:536–568

}

void TableScan::estimateBytesPerRow(
    const std::optional<RowVectorPtr>& dataOptional) {
  if (!enableEstimateBytesPerRow_ || !dataOptional || !dataOptional.value()) {
    return;
  }
  auto size = dataOptional.value()->size();
  if (size <= 0) {
    return;
  }

  auto batchByets = dataOptional.value()->usedSize();
  auto bytesPerRow = batchByets / size;

  auto adjustBatchSizeFactor = [this]() {
    estimateBatchSizeFactor_ =
        std::max(estimateBatchSizeFactor_ / 2, MinEstimateBatchSizeFactor);
  };
  auto isLargeDiff = [this](int64_t l, int64_t r, int32_t multiples) -> bool {
    return l * multiples / estimateBatchSizeFactor_ < r ||
        l > r * multiples / estimateBatchSizeFactor_;
  };

  if (bytesPerRowAverage_ > 0 &&
      isLargeDiff(bytesPerRow, bytesPerRowAverage_, 5)) {
    adjustBatchSizeFactor();
    bytesPerRowAverage_ = 0;
  } else if (
      bytesPerRowLastBatch_.has_value() &&
      isLargeDiff(bytesPerRow, bytesPerRowLastBatch_.value(), 3)) {
    adjustBatchSizeFactor();
  }
  bytesPerRowLastBatch_ = bytesPerRow;
}

void TableScan::close() {
  if (dataSource_) {