org.apache.calcite.rel.rules

Class MultiJoinProjectTransposeRule

java.lang.Object

org.apache.calcite.plan.RelOptRule

org.apache.calcite.plan.RelRule<JoinProjectTransposeRule.Config>

org.apache.calcite.rel.rules.JoinProjectTransposeRule

org.apache.calcite.rel.rules.MultiJoinProjectTransposeRule

All Implemented Interfaces:

TransformationRule

@Value.Enclosing
public class MultiJoinProjectTransposeRule
extends JoinProjectTransposeRule

MultiJoinProjectTransposeRule implements the rule for pulling LogicalProjects that are on top of a MultiJoin and beneath a LogicalJoin so the LogicalProject appears above the LogicalJoin.

In the process of doing so, also save away information about the respective fields that are referenced in the expressions in the LogicalProject we're pulling up, as well as the join condition, in the resultant MultiJoins

For example, if we have the following sub-query:

 (select X.x1, Y.y1 from X, Y
  where X.x2 = Y.y2 and X.x3 = 1 and Y.y3 = 2)

The MultiJoin associated with (X, Y) associates x1 with X and y1 with Y. Although x3 and y3 need to be read due to the filters, they are not required after the row scan has completed and therefore are not saved. The join fields, x2 and y2, are also tracked separately.

Note that by only pulling up projects that are on top of MultiJoins, we preserve projections on top of row scans.

See the superclass for details on restrictions regarding which LogicalProjects cannot be pulled.

See Also:

CoreRules.MULTI_JOIN_BOTH_PROJECT, CoreRules.MULTI_JOIN_LEFT_PROJECT, CoreRules.MULTI_JOIN_RIGHT_PROJECT

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	MultiJoinProjectTransposeRule.Config Rule configuration.

Nested classes/interfaces inherited from class org.apache.calcite.plan.RelRule

RelRule.Done, RelRule.MatchHandler<R extends RelOptRule>, RelRule.OperandBuilder, RelRule.OperandDetailBuilder<R extends RelNode>, RelRule.OperandTransform

Nested classes/interfaces inherited from class org.apache.calcite.plan.RelOptRule

RelOptRule.ConverterRelOptRuleOperand

Field Summary

Fields inherited from class org.apache.calcite.plan.RelRule

config

Fields inherited from class org.apache.calcite.plan.RelOptRule

description, operands, relBuilderFactory

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	MultiJoinProjectTransposeRule(MultiJoinProjectTransposeRule.Config config) Creates a MultiJoinProjectTransposeRule.
	MultiJoinProjectTransposeRule(RelOptRuleOperand operand, RelBuilderFactory relBuilderFactory, String description) Deprecated.
	MultiJoinProjectTransposeRule(RelOptRuleOperand operand, String description) Deprecated.

Method Summary

Modifier and Type	Method and Description
protected RelNode	getProjectChild(RelOptRuleCall call, Project project, boolean leftChild) Returns the child of the project that will be used as input into the new LogicalJoin once the projects are pulled above the LogicalJoin.
protected Project	getRightChild(RelOptRuleCall call) Returns the Project corresponding to the right child.
protected boolean	hasLeftChild(RelOptRuleCall call) Returns whether the rule was invoked with a left project child.
protected boolean	hasRightChild(RelOptRuleCall call) Returns whether the rule was invoked with 2 children.

Methods inherited from class org.apache.calcite.rel.rules.JoinProjectTransposeRule

createProjectExprs, onMatch

Methods inherited from class org.apache.calcite.plan.RelOptRule

any, convert, convert, convertList, convertOperand, convertOperand, equals, equals, getOperand, getOperands, getOutConvention, getOutTrait, hashCode, matches, none, operand, operand, operand, operand, operand, operandJ, operandJ, some, toString, unordered

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

MultiJoinProjectTransposeRule

protected MultiJoinProjectTransposeRule(MultiJoinProjectTransposeRule.Config config)

Creates a MultiJoinProjectTransposeRule.

MultiJoinProjectTransposeRule

@Deprecated
public MultiJoinProjectTransposeRule(RelOptRuleOperand operand,
                                                 String description)

Deprecated.

MultiJoinProjectTransposeRule

@Deprecated
public MultiJoinProjectTransposeRule(RelOptRuleOperand operand,
                                                 RelBuilderFactory relBuilderFactory,
                                                 String description)

Deprecated.

Method Detail

hasLeftChild

protected boolean hasLeftChild(RelOptRuleCall call)

Description copied from class: JoinProjectTransposeRule

Returns whether the rule was invoked with a left project child.

Overrides:

hasLeftChild in class JoinProjectTransposeRule

hasRightChild

protected boolean hasRightChild(RelOptRuleCall call)

Description copied from class: JoinProjectTransposeRule

Returns whether the rule was invoked with 2 children.

Overrides:

hasRightChild in class JoinProjectTransposeRule

getRightChild

protected Project getRightChild(RelOptRuleCall call)

Description copied from class: JoinProjectTransposeRule

Returns the Project corresponding to the right child.

Overrides:

getRightChild in class JoinProjectTransposeRule

getProjectChild

protected RelNode getProjectChild(RelOptRuleCall call,
                                  Project project,
                                  boolean leftChild)

Description copied from class: JoinProjectTransposeRule

Returns the child of the project that will be used as input into the new LogicalJoin once the projects are pulled above the LogicalJoin.

Overrides:

getProjectChild in class JoinProjectTransposeRule

Parameters:

call - RelOptRuleCall

project - project RelNode

leftChild - true if the project corresponds to the left projection

Returns:

child of the project that will be used as input into the new LogicalJoin once the projects are pulled above the LogicalJoin