org.eigenbase.rel
Class AggregateRel

java.lang.Object
  org.eigenbase.rel.AbstractRelNode
      org.eigenbase.rel.SingleRel
          org.eigenbase.rel.AggregateRelBase
              org.eigenbase.rel.AggregateRel

All Implemented Interfaces:

Cloneable, RelNode

public final class AggregateRel
extends AggregateRelBase

AggregateRel is a relational operator which eliminates duplicates and computes totals.

Rules:

• PullConstantsThroughAggregatesRule
• RemoveDistinctAggregateRule
• ReduceAggregatesRule.

  Since:

  3 February, 2002

  Version:

  $Id: //open/dev/farrago/src/org/eigenbase/rel/AggregateRel.java#18 $

  Author:

  jhyde

  Nested Class Summary

  Nested classes/interfaces inherited from class org.eigenbase.rel.AggregateRelBase

  AggregateRelBase.AggCallBinding

  Field Summary

  Fields inherited from class org.eigenbase.rel.AggregateRelBase

  aggCalls, groupCount

  Fields inherited from class org.eigenbase.rel.AbstractRelNode

  digest, id, nextId, rowType, traits

  Fields inherited from interface org.eigenbase.rel.RelNode

  emptyArray

  Constructor Summary

  AggregateRel(RelOptCluster cluster, RelNode child, int groupCount, List<AggregateCall> aggCalls)
  Creates an AggregateRel.

  Method Summary

  AggregateRel

  clone() Clones this RelNode.

  Methods inherited from class org.eigenbase.rel.AggregateRelBase

  computeSelfCost, containsDistinctCall, deriveRowType, explain, getAggCallList, getGroupCount, getRows, isDistinct

  Methods inherited from class org.eigenbase.rel.SingleRel

  childrenAccept, getChild, getInputs, replaceInput

  Methods inherited from class org.eigenbase.rel.AbstractRelNode

  cloneTraits, collectVariablesSet, collectVariablesUsed, computeDigest, getChildExps, getCluster, getCollationList, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getOrCreateCorrelVariable, getQuery, getRelTypeName, getRowType, getTable, getTraits, getVariablesStopped, inheritTraitsFrom, isAccessTo, isValid, onRegister, recomputeDigest, register, registerCorrelVariable, setCorrelVariable, toString

  Methods inherited from class java.lang.Object

  equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  Constructor Detail

  AggregateRel

  public AggregateRel(RelOptCluster cluster,
                      RelNode child,
                      int groupCount,
                      List<AggregateCall> aggCalls)

  Creates an AggregateRel.

  Parameters:

  cluster - RelOptCluster this relational expression belongs to

  child - input relational expression

  groupCount - Number of columns to group on

  aggCalls - Array of aggregates to compute

  "Precondition:"

  aggCalls != null

  Method Detail

  clone

  public AggregateRel clone()

  Description copied from interface: RelNode

  Clones this RelNode.

  Traits of the RelNode must be explicitly cloned, using AbstractRelNode.inheritTraitsFrom(AbstractRelNode), as the RelNode may have traits of which it has no knowledge. Example implementation:

       public MyRelNode clone()
       {
           MyRelNode clone = new MyRelNode(...);
           clone.inheritTraitsFrom(this);
           return clone;
       }
   

  N.B.: This method must be overridden whenever an existing, concrete RelNode is extended. Otherwise, calling clone() will produce a differently typed RelNode, resulting in invalid or incorrect query plans.

  Specified by:

  clone in interface RelNode

  Specified by:

  clone in class AbstractRelNode

  Returns:

  a clone of this RelNode