saffron.rel
Class Aggregate

java.lang.Object
  |
  +--saffron.rel.Rel
        |
        +--saffron.rel.SingleRel
              |
              +--saffron.rel.Aggregate

Direct Known Subclasses:

JavaAggregate

public class Aggregate

extends SingleRel

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

Since:

3 February, 2002

Version:

$Id: //open/saffron/src/main/saffron/rel/Aggregate.java#8 $

Author:

jhyde

Nested Class Summary

static class	Aggregate.Call
private static class	Aggregate.ConvertToJavaRule

Nested classes inherited from class saffron.rel.Rel

Field Summary

protected Aggregate.Call[]	aggCalls
protected int	groupCount

Fields inherited from class saffron.rel.SingleRel

child

Fields inherited from class saffron.rel.Rel

cluster, digest, emptyArray, id, nextId, rowType

Constructor Summary

Aggregate(Cluster cluster, Rel child, int groupCount, Aggregate.Call[] aggCalls)

Method Summary

Object	clone()
Cost	computeSelfCost(Planner planner) Returns the cost of this plan (not including children).
protected Type	deriveRowType()
Aggregate.Call[]	getAggCalls()
int	getGroupCount()
static void	register(Planner planner) See Rel.register(saffron.Planner).

Methods inherited from class saffron.rel.SingleRel

childrenAccept, explain, getInputs, replaceInput

Methods inherited from class saffron.rel.Rel

computeDigest, getChildExps, getCluster, getConvention, getCorelVariable, getEnvironment, getId, getInput, getOrCreateCorelVariable, getParentEnv, getQualifier, getQuery, getRelTypeName, getRows, getRowType, getTable, getType, getVariablesStopped, implement, implementExp, implementExps, implementFieldAccess, implementSelf, isAccessTo, isDistinct, onRegister, recomputeDigest, registerCorelVariable, setCorelVariable, toString

Methods inherited from class java.lang.Object

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

Field Detail

groupCount

protected int groupCount

aggCalls

protected Aggregate.Call[] aggCalls

Constructor Detail

Aggregate

public Aggregate(Cluster cluster,
                 Rel child,
                 int groupCount,
                 Aggregate.Call[] aggCalls)

Method Detail

clone

public Object clone()

Specified by:

clone in class Rel

getGroupCount

public int getGroupCount()

getAggCalls

public Aggregate.Call[] getAggCalls()

deriveRowType

protected Type deriveRowType()

Overrides:

deriveRowType in class SingleRel

computeSelfCost

public Cost computeSelfCost(Planner planner)

Description copied from class: Rel

Returns the cost of this plan (not including children). The base implementation throws an error; derived classes should override.

Overrides:

computeSelfCost in class Rel

register

public static void register(Planner planner)

See Rel.register(saffron.Planner).