Method estimateOutputRowSize

bolt/exec/GroupingSet.cpp:2156–2175

        &aggregateVector);
  }
  if (intermediateRows_) {
    intermediateRows_->eraseRowsSkippingKeys(folly::Range<char**>(
        intermediateGroups_.data(), intermediateGroups_.size()));
    if (intermediateRows_->checkFree()) {
      intermediateRows_->stringAllocator().checkEmpty();
    }
  }

  // It's unnecessary to call function->clear() to reset the internal states of
  // aggregation functions because toIntermediate() is already called at the end
  // of HashAggregation::getOutput(). When toIntermediate() is called, the
  // aggregaiton function instances won't be reused after it returns.
  tempVectors_.clear();
}

std::optional<int64_t> GroupingSet::estimateOutputRowSize() const {
  if (table_ == nullptr || table_->numDistinct() == 0) {
    return std::nullopt;
  }

  const auto rowSizeFromContainer = table_->rows()->estimateRowSize();
  if (!hasExternalMemoryAccumulators_) {
    return rowSizeFromContainer;