org.eigenbase.relopt
Class RelOptRuleCall

java.lang.Object
  org.eigenbase.relopt.RelOptRuleCall

Direct Known Subclasses:

HepRuleCall, MockRelOptPlanner.MockRuleCall, Rex2CalcPlanTest.TesterImpl.MyRelOptRuleCall, VolcanoRuleCall

public abstract class RelOptRuleCall
extends Object

A RelOptRuleCall is an invocation of a RelOptRule with a set of relational expressions as arguments.

Field Summary

private Map<RelNode,List<RelNode>>	nodeChildren
private RelOptRuleOperand	operand0
private List<RelNode>	parents
private RelOptPlanner	planner
RelNode[]	rels
private RelOptRule	rule
protected static Logger	tracer

Constructor Summary

protected	RelOptRuleCall(RelOptPlanner planner, RelOptRuleOperand operand, RelNode[] rels, Map<RelNode,List<RelNode>> nodeChildren)
protected	RelOptRuleCall(RelOptPlanner planner, RelOptRuleOperand operand, RelNode[] rels, Map<RelNode,List<RelNode>> nodeChildren, List<RelNode> parents) Creates a RelOptRuleCall.

Method Summary

List<RelNode>	getChildRels(RelNode rel) Returns the children of a given relational expression node matched in a rule.
RelOptRuleOperand	getOperand0() Returns the root operand matched by this rule.
List<RelNode>	getParents()
RelOptPlanner	getPlanner() Returns the planner.
RelNode[]	getRels() Returns a list of matched relational expressions.
RelOptRule	getRule() Returns the invoked planner rule.
abstract void	transformTo(RelNode rel) Called by the rule whenever it finds a match.

Methods inherited from class java.lang.Object

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

Field Detail

tracer

protected static final Logger tracer

operand0

private final RelOptRuleOperand operand0

nodeChildren

private final Map<RelNode,List<RelNode>> nodeChildren

rule

private final RelOptRule rule

rels

public final RelNode[] rels

planner

private final RelOptPlanner planner

parents

private final List<RelNode> parents

Constructor Detail

RelOptRuleCall

protected RelOptRuleCall(RelOptPlanner planner,
                         RelOptRuleOperand operand,
                         RelNode[] rels,
                         Map<RelNode,List<RelNode>> nodeChildren,
                         List<RelNode> parents)

Creates a RelOptRuleCall.

Parameters:

planner - Planner

operand - Root operand

rels - Array of relational expressions which matched each operand

nodeChildren - For each node which matched with matchAnyChildren=true, a list of the node's children

parents - list of parent RelNodes corresponding to the first relational expression in the array argument, if known; otherwise, null

RelOptRuleCall

protected RelOptRuleCall(RelOptPlanner planner,
                         RelOptRuleOperand operand,
                         RelNode[] rels,
                         Map<RelNode,List<RelNode>> nodeChildren)

Method Detail

getOperand0

public RelOptRuleOperand getOperand0()

Returns the root operand matched by this rule.

Returns:

root operand

getRule

public RelOptRule getRule()

Returns the invoked planner rule.

Returns:

planner rule

getRels

public RelNode[] getRels()

Returns a list of matched relational expressions.

Returns:

matched relational expressions

getChildRels

public List<RelNode> getChildRels(RelNode rel)

Returns the children of a given relational expression node matched in a rule.

If the operand which caused the match has RelOptRuleOperand.matchAnyChildren=false, the children will have their own operands and therefore be easily available in the array returned by the getRels() method, so this method returns null.

This method is for RelOptRuleOperand.matchAnyChildren=true, which is generally used when a node can have a variable number of children, and hence where the matched children are not retrievable by any other means.

Parameters:

rel - Relational expression

Returns:

Children of relational expression

getPlanner

public RelOptPlanner getPlanner()

Returns the planner.

Returns:

planner

getParents

public List<RelNode> getParents()

Returns:

list of parents of the first relational expression

transformTo

public abstract void transformTo(RelNode rel)

Called by the rule whenever it finds a match. The implementation of this method will guarantee that the original relational expression (e.g., this.rels[0]) has its traits propagated to the new relational expression (rel) and its unregistered children. Any trait not specifically set in the RelTraitSet returned by rel.getTraits() will be copied from this.rels[0].getTraitSet().