Package org.apache.druid.segment.join

Class NoopJoinableFactory

java.lang.Object

org.apache.druid.segment.join.NoopJoinableFactory

All Implemented Interfaces:

JoinableFactory

public class NoopJoinableFactory
extends Object
implements JoinableFactory

Field Summary

Fields

Modifier and Type	Field	Description
static final NoopJoinableFactory	INSTANCE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	NoopJoinableFactory()

Method Summary

Modifier and Type	Method	Description
Optional<Joinable>	build(DataSource dataSource, JoinConditionAnalysis condition)	Create a Joinable object.
boolean	isDirectlyJoinable(DataSource dataSource)	Returns true if a Joinable **may** be created for a given DataSource, but is not a guarantee that JoinableFactory.build(org.apache.druid.query.DataSource, org.apache.druid.segment.join.JoinConditionAnalysis) will return a non-empty result.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.druid.segment.join.JoinableFactory

computeJoinCacheKey

Field Details

INSTANCE

public static final NoopJoinableFactory INSTANCE

Constructor Details

NoopJoinableFactory

protected NoopJoinableFactory()

Method Details

isDirectlyJoinable

public boolean isDirectlyJoinable(DataSource dataSource)

Description copied from interface: JoinableFactory

Returns true if a Joinable **may** be created for a given DataSource, but is not a guarantee that JoinableFactory.build(org.apache.druid.query.DataSource, org.apache.druid.segment.join.JoinConditionAnalysis) will return a non-empty result. Successfully building a Joinable might require specific criteria of the JoinConditionAnalysis.

Specified by:

isDirectlyJoinable in interface JoinableFactory

build

public Optional<Joinable> build(DataSource dataSource,
 JoinConditionAnalysis condition)

Description copied from interface: JoinableFactory

Create a Joinable object. This may be an expensive operation involving loading data, creating a hash table, etc.

Specified by:

build in interface JoinableFactory

Parameters:

dataSource - the datasource to join on

condition - the condition to join on

Returns:

a Joinable if this datasource + condition combo is joinable; empty if not