import org.apache.calcite.rel.stream.Delta; //导入依赖的package包/类
private RelCollation requiredCollation(RelNode r) {
	if (r instanceof Sort) {
		return ((Sort) r).collation;
	}
	if (r instanceof Project) {
		return requiredCollation(((Project) r).getInput());
	}
	if (r instanceof Delta) {
		return requiredCollation(((Delta) r).getInput());
	}
	throw new AssertionError();
}
 

import org.apache.calcite.rel.stream.Delta; //导入依赖的package包/类
@Override
public RelInfo visit(RelContext context, RelNode node, List<RelInfo> inputStreams)
{
  Delta delta = (Delta)node;

  ConsoleOutputOperator console = context.dag
      .addOperator(OperatorUtils.getUniqueOperatorName(delta.getRelTypeName()), ConsoleOutputOperator.class);
  console.setStringFormat("Delta Record: %s");

  return new RelInfo("Delta", Lists.<Operator.InputPort>newArrayList(console.input), console, null,
      delta.getRowType());
}
 

import org.apache.calcite.rel.stream.Delta; //导入依赖的package包/类
public final T traverse(RelNode n) throws Exception {
  List<T> inputStreams = new ArrayList<>();
  for (RelNode input : n.getInputs()) {
    inputStreams.add(traverse(input));
  }

  if (n instanceof Aggregate) {
    return visitAggregate((Aggregate) n, inputStreams);
  } else if (n instanceof Calc) {
    return visitCalc((Calc) n, inputStreams);
  } else if (n instanceof Collect) {
    return visitCollect((Collect) n, inputStreams);
  } else if (n instanceof Correlate) {
    return visitCorrelate((Correlate) n, inputStreams);
  } else if (n instanceof Delta) {
    return visitDelta((Delta) n, inputStreams);
  } else if (n instanceof Exchange) {
    return visitExchange((Exchange) n, inputStreams);
  } else if (n instanceof Project) {
    return visitProject((Project) n, inputStreams);
  } else if (n instanceof Filter) {
    return visitFilter((Filter) n, inputStreams);
  } else if (n instanceof Sample) {
    return visitSample((Sample) n, inputStreams);
  } else if (n instanceof Sort) {
    return visitSort((Sort) n, inputStreams);
  } else if (n instanceof TableModify) {
    return visitTableModify((TableModify) n, inputStreams);
  } else if (n instanceof TableScan) {
    return visitTableScan((TableScan) n, inputStreams);
  } else if (n instanceof Uncollect) {
    return visitUncollect((Uncollect) n, inputStreams);
  } else if (n instanceof Window) {
    return visitWindow((Window) n, inputStreams);
  } else if (n instanceof Join) {
    return visitJoin((Join) n, inputStreams);
  } else {
    return defaultValue(n, inputStreams);
  }
}
 

import org.apache.calcite.rel.stream.Delta; //导入依赖的package包/类
private RelCollation requiredCollation(RelNode r) {
  if (r instanceof Sort) {
    return ((Sort) r).collation;
  }
  if (r instanceof Project) {
    return requiredCollation(((Project) r).getInput());
  }
  if (r instanceof Delta) {
    return requiredCollation(((Delta) r).getInput());
  }
  throw new AssertionError();
}
 

import org.apache.calcite.rel.stream.Delta; //导入依赖的package包/类
public T visitDelta(Delta delta, List<T> inputStreams) throws Exception {
  return defaultValue(delta, inputStreams);
}
 

import org.apache.calcite.rel.stream.Delta; //导入依赖的package包/类
@Override
public Void visitDelta(Delta delta, List<Void> inputStreams) throws Exception {
  pw.print(String.format(STAGE_PASSTHROUGH, getStageName(delta)));
  return null;
}