org.apache.calcite.rel.hint

Class HintStrategyTable

java.lang.Object

org.apache.calcite.rel.hint.HintStrategyTable

public class HintStrategyTable
extends Object

A collection of HintStrategys.

Every hint must register a HintStrategy into the collection. With a hint strategies mapping, the hint strategy table is used as a tool to decide i) if the given hint was registered; ii) which hints are suitable for the rel with a given hints collection; iii) if the hint options are valid.

The hint strategy table is immutable. To create one, use builder().

Match of hint name is case insensitive.

See Also:

HintPredicate

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	HintStrategyTable.Builder Builder for HintStrategyTable.
static class	HintStrategyTable.HintErrorLogger Implementation of Litmus that returns a status code, it logs warnings for fail check and does not throw.

Field Summary

Fields

Modifier and Type	Field and Description
static HintStrategyTable	EMPTY Empty strategies.

Method Summary

Modifier and Type	Method and Description
List<RelHint>	apply(List<RelHint> hints, RelNode rel) Applies this HintStrategyTable hint strategies to the given relational expression and the hints.
static HintStrategyTable.Builder	builder() Returns a HintStrategyTable builder.
boolean	isRuleExcluded(Hintable hintable, RelOptRule rule) Returns whether the hintable has hints that imply the given rule should be excluded.
boolean	validateHint(RelHint hint) Checks if the given hint is valid.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY

public static final HintStrategyTable EMPTY

Empty strategies.

Method Detail

apply

public List<RelHint> apply(List<RelHint> hints,
                           RelNode rel)

Applies this HintStrategyTable hint strategies to the given relational expression and the hints.

Parameters:

hints - Hints that may attach to the rel

rel - Relational expression

Returns:

A hint list that can be attached to the rel

validateHint

public boolean validateHint(RelHint hint)

Checks if the given hint is valid.

Parameters:

hint - The hint

isRuleExcluded

public boolean isRuleExcluded(Hintable hintable,
                              RelOptRule rule)

Returns whether the hintable has hints that imply the given rule should be excluded.

builder

public static HintStrategyTable.Builder builder()

Returns a HintStrategyTable builder.