saffron.opt
Class Cluster

java.lang.Object
  |
  +--saffron.opt.Cluster

public class Cluster

extends Object

A Cluster is a collection of Relational expressions which have the same environment.

See the comment against saffron.rel.QueryInfo on why you should put fields in that class, not this one.

Since:

27 September, 2001

Version:

$Id: //open/saffron/src/main/saffron/opt/Cluster.java#3 $

Author:

jhyde

Field Summary

Environment	env
private Expression	originalExpression
(package private) VolcanoPlanner	planner
Query	query
TypeFactory	typeFactory

Constructor Summary

(package private)

Cluster(Query query, Environment env, VolcanoPlanner planner, Expression originalExpression, TypeFactory typeFactory) Creates a cluster.

Method Summary

Expression	getOriginalExpression()
Planner	getPlanner()

Methods inherited from class java.lang.Object

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

Field Detail

query

public final Query query

env

public final Environment env

originalExpression

private final Expression originalExpression

planner

final VolcanoPlanner planner

typeFactory

public final TypeFactory typeFactory

Constructor Detail

Cluster

Cluster(Query query,
        Environment env,
        VolcanoPlanner planner,
        Expression originalExpression,
        TypeFactory typeFactory)

Creates a cluster.

Pre-condition:

planner != null, typeFactory != null

Method Detail

getOriginalExpression

public Expression getOriginalExpression()

getPlanner

public Planner getPlanner()