Method GetNextLeftSemiJoin

be/src/exec/nested-loop-join-node.cc:332–375

}

Status NestedLoopJoinNode::GetNextLeftSemiJoin(RuntimeState* state,
    RowBatch* output_batch) {
  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());
  const int N = BitUtil::RoundUpToPowerOfTwo(state->batch_size());

  while (!eos_) {
    DCHECK(HasValidProbeRow());
    while (!build_row_iterator_.AtEnd()) {
      DCHECK(HasValidProbeRow());
      CreateOutputRow(semi_join_staging_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) {
        RETURN_IF_CANCELLED(state);
        RETURN_IF_ERROR(QueryMaintenance(state));
      }
      if (!EvalConjuncts(
              join_conjunct_evals, num_join_conjuncts, semi_join_staging_row_)) {
        continue;
      }
      // A match is found. Create the output row from the probe row.
      TupleRow* output_row = output_batch->GetRow(output_batch->AddRow());
      output_batch->CopyRow(current_probe_row_, output_row);
      VLOG_ROW << "match row: " << PrintRow(output_row, *row_desc());
      output_batch->CommitLastRow();
      IncrementNumRowsReturned(1);
      if (ReachedLimit()) {
        eos_ = true;
        return Status::OK();
      }
      // Stop scanning the build rows for the current probe row. If we reach
      // this point, we already have a match for this probe row.
      break;
    }
    RETURN_IF_ERROR(NextProbeRow(state, output_batch));
    if (output_batch->AtCapacity()) break;
  }
  return Status::OK();
}

Status NestedLoopJoinNode::GetNextLeftAntiJoin(RuntimeState* state,
    RowBatch* output_batch) {