Package org.apache.calcite.plan.hep

Class HepPlanner

java.lang.Object

org.apache.calcite.plan.AbstractRelOptPlanner

org.apache.calcite.plan.hep.HepPlanner

All Implemented Interfaces:

RelOptPlanner

public class HepPlanner
extends AbstractRelOptPlanner

HepPlanner is a heuristic implementation of the RelOptPlanner interface.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.calcite.plan.RelOptPlanner

RelOptPlanner.CannotPlanException, RelOptPlanner.Executor

Field Summary

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

cancelFlag, context, costFactory, mapDescToRule

Fields inherited from interface org.apache.calcite.plan.RelOptPlanner

LOGGER

Constructor Summary

Constructors

Constructor	Description
HepPlanner(HepProgram program)	Creates a new HepPlanner that allows DAG.
HepPlanner(HepProgram program, Context context)	Creates a new HepPlanner that allows DAG.
HepPlanner(HepProgram program, Context context, boolean noDag, Function2<RelNode,RelNode,Void> onCopyHook, RelOptCostFactory costFactory)	Creates a new HepPlanner with the option to keep the graph a tree (noDag = true) or allow DAG (noDag = false).

Method Summary

Modifier and Type	Method	Description
void	addMaterialization(RelOptMaterialization materialization)	Defines a pair of relational expressions that are equivalent.
RelNode	changeTraits(RelNode rel, RelTraitSet toTraits)	Changes a relational expression to an equivalent one with a different set of traits.
void	clear()	Removes all internal state, including all registered rules, materialized views, and lattices.
RelNode	ensureRegistered(RelNode rel, RelNode equivRel)	Registers a relational expression if it is not already registered.
RelNode	findBestExp()	Finds the most efficient expression to implement this query.
com.google.common.collect.ImmutableList<RelOptMaterialization>	getMaterializations()	Returns the materializations that have been registered with the planner.
long	getRelMetadataTimestamp(RelNode rel)	Gets a timestamp for a given rel's metadata.
RelNode	getRoot()	Returns the root node of this query.
boolean	isRegistered(RelNode rel)	Determines whether a relational expression has been registered.
void	onCopy(RelNode rel, RelNode newRel)	Called when a relational expression is copied to a similar expression.
RelNode	register(RelNode rel, RelNode equivRel)	Registers a relational expression in the expression bank.
void	registerMetadataProviders(List<RelMetadataProvider> list)	Gives this planner a chance to register one or more RelMetadataProviders in the chain which will be used to answer metadata queries.
void	setRoot(RelNode rel)	Sets the root node of this query.

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

addLattice, addListener, addRelTraitDef, addRule, checkCancel, chooseDelegate, clearRelTraitDefs, dumpRuleAttemptsInfo, emptyTraitSet, fireRule, getContext, getCost, getCost, getCostFactory, getExecutor, getLattice, getListener, getRelTraitDefs, getRuleByDescription, getRules, isRuleExcluded, notifyChosen, notifyDiscard, notifyEquivalence, notifyTransformation, onNewClass, prune, registerClass, registerSchema, removeRule, setCancelFlag, setExecutor, setRuleDescExclusionFilter, subClasses

Methods inherited from class java.lang.Object

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

Constructor Detail

HepPlanner

public HepPlanner(HepProgram program)

Creates a new HepPlanner that allows DAG.

Parameters:

program - program controlling rule application

HepPlanner

public HepPlanner(HepProgram program,
                  Context context)

Creates a new HepPlanner that allows DAG.

Parameters:

program - program controlling rule application

context - to carry while planning

HepPlanner

public HepPlanner(HepProgram program,
                  Context context,
                  boolean noDag,
                  Function2<RelNode,RelNode,Void> onCopyHook,
                  RelOptCostFactory costFactory)

Creates a new HepPlanner with the option to keep the graph a tree (noDag = true) or allow DAG (noDag = false).

Parameters:

noDag - If false, create shared nodes if expressions are identical

program - Program controlling rule application

onCopyHook - Function to call when a node is copied

Method Detail

setRoot

public void setRoot(RelNode rel)

Description copied from interface: RelOptPlanner

Sets the root node of this query.

Parameters:

rel - Relational expression

getRoot

public RelNode getRoot()

Description copied from interface: RelOptPlanner

Returns the root node of this query.

Returns:

Root node

clear

public void clear()

Description copied from interface: RelOptPlanner

Removes all internal state, including all registered rules, materialized views, and lattices.

Specified by:

clear in interface RelOptPlanner

Overrides:

clear in class AbstractRelOptPlanner

changeTraits

public RelNode changeTraits(RelNode rel,
                            RelTraitSet toTraits)

Description copied from interface: RelOptPlanner

Changes a relational expression to an equivalent one with a different set of traits.

Parameters:

rel - Relational expression (may or may not have been registered; must not have the desired traits)

toTraits - Trait set to convert the relational expression to

Returns:

Relational expression with desired traits. Never null, but may be abstract

findBestExp

public RelNode findBestExp()

Description copied from interface: RelOptPlanner

Finds the most efficient expression to implement this query.

register

public RelNode register(RelNode rel,
                        RelNode equivRel)

Description copied from interface: RelOptPlanner

Registers a relational expression in the expression bank.

After it has been registered, you may not modify it.

The expression must not already have been registered. If you are not sure whether it has been registered, call RelOptPlanner.ensureRegistered(RelNode, RelNode).

Parameters:

rel - Relational expression to register (must not already be registered)

equivRel - Relational expression it is equivalent to (may be null)

Returns:

the same expression, or an equivalent existing expression

onCopy

public void onCopy(RelNode rel,
                   RelNode newRel)

Description copied from interface: RelOptPlanner

Called when a relational expression is copied to a similar expression.

Specified by:

onCopy in interface RelOptPlanner

Overrides:

onCopy in class AbstractRelOptPlanner

ensureRegistered

public RelNode ensureRegistered(RelNode rel,
                                RelNode equivRel)

Description copied from interface: RelOptPlanner

Registers a relational expression if it is not already registered.

If equivRel is specified, rel is placed in the same equivalence set. It is OK if equivRel has different traits; rel will end up in a different subset of the same set.

It is OK if rel is a subset.

Parameters:

rel - Relational expression to register

equivRel - Relational expression it is equivalent to (may be null)

Returns:

Registered relational expression

isRegistered

public boolean isRegistered(RelNode rel)

Description copied from interface: RelOptPlanner

Determines whether a relational expression has been registered.

Parameters:

rel - expression to test

Returns:

whether rel has been registered

registerMetadataProviders

public void registerMetadataProviders(List<RelMetadataProvider> list)

Description copied from interface: RelOptPlanner

Gives this planner a chance to register one or more RelMetadataProviders in the chain which will be used to answer metadata queries.

Planners which use their own relational expressions internally to represent concepts such as equivalence classes will generally need to supply corresponding metadata providers.

Specified by:

registerMetadataProviders in interface RelOptPlanner

Overrides:

registerMetadataProviders in class AbstractRelOptPlanner

Parameters:

list - receives planner's custom providers, if any

getRelMetadataTimestamp

public long getRelMetadataTimestamp(RelNode rel)

Description copied from interface: RelOptPlanner

Gets a timestamp for a given rel's metadata. This timestamp is used by CachingRelMetadataProvider to decide whether cached metadata has gone stale.

Specified by:

getRelMetadataTimestamp in interface RelOptPlanner

Overrides:

getRelMetadataTimestamp in class AbstractRelOptPlanner

Parameters:

rel - rel of interest

Returns:

timestamp of last change which might affect metadata derivation

getMaterializations

public com.google.common.collect.ImmutableList<RelOptMaterialization> getMaterializations()

Description copied from interface: RelOptPlanner

Returns the materializations that have been registered with the planner.

Specified by:

getMaterializations in interface RelOptPlanner

Overrides:

getMaterializations in class AbstractRelOptPlanner

addMaterialization

public void addMaterialization(RelOptMaterialization materialization)

Description copied from interface: RelOptPlanner

Defines a pair of relational expressions that are equivalent.

Typically tableRel is a LogicalTableScan representing a table that is a materialized view and queryRel is the SQL expression that populates that view. The intention is that tableRel is cheaper to evaluate and therefore if the query being optimized uses (or can be rewritten to use) queryRel as a sub-expression then it can be optimized by using tableRel instead.

Specified by:

addMaterialization in interface RelOptPlanner

Overrides:

addMaterialization in class AbstractRelOptPlanner