Method FindBuildMatches

be/src/exec/nested-loop-join-node.cc:621–667

}

Status NestedLoopJoinNode::FindBuildMatches(
    RuntimeState* state, RowBatch* output_batch, bool* return_output_batch) {
  *return_output_batch = false;
  ScalarExprEvaluator* const* join_conjunct_evals = join_conjunct_evals_.data();
  size_t num_join_conjuncts = join_conjuncts_.size();
  DCHECK_EQ(num_join_conjuncts, join_conjunct_evals_.size());
  ScalarExprEvaluator* const* conjunct_evals = conjunct_evals_.data();
  size_t num_conjuncts = conjuncts_.size();
  DCHECK_EQ(num_conjuncts, conjunct_evals_.size());

  const int N = BitUtil::RoundUpToPowerOfTwo(state->batch_size());
  while (!build_row_iterator_.AtEnd()) {
    DCHECK(current_probe_row_ != NULL);
    TupleRow* output_row = output_batch->GetRow(output_batch->AddRow());
    CreateOutputRow(output_row, current_probe_row_, build_row_iterator_.GetRow());
    build_row_iterator_.Next();
    ++current_build_row_idx_;

    // This loop can go on for a long time if the conjuncts are very selective. Do
    // expensive query maintenance after every N iterations.
    if ((current_build_row_idx_ & (N - 1)) == 0) {
      if (ReachedLimit()) {
        eos_ = true;
        *return_output_batch = true;
        return Status::OK();
      }
      RETURN_IF_CANCELLED(state);
      RETURN_IF_ERROR(QueryMaintenance(state));
    }
    if (!EvalConjuncts(join_conjunct_evals, num_join_conjuncts, output_row)) {
      continue;
    }
    matched_probe_ = true;
    if (matching_build_rows_ != NULL) {
      matching_build_rows_->Set(current_build_row_idx_ - 1, true);
    }
    if (!EvalConjuncts(conjunct_evals, num_conjuncts, output_row)) continue;
    VLOG_ROW << "match row: " << PrintRow(output_row, *row_desc());
    output_batch->CommitLastRow();
    IncrementNumRowsReturned(1);
    if (output_batch->AtCapacity()) {
      *return_output_batch = true;
      return Status::OK();
    }
  }
  return Status::OK();
}

Status NestedLoopJoinNode::NextProbeRow(RuntimeState* state, RowBatch* output_batch) {
  current_probe_row_ = NULL;