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LongHashedRelation

LongHashedRelation is a HashedRelation that is used when HashedRelation is requested for a concrete HashedRelation instance when the single key is of type long.

LongHashedRelation is also a Java Externalizable, i.e. when persisted, only the identity is written in the serialization stream and it is the responsibility of the class to <> and <> the contents of its instances.

LongHashedRelation is <> when:

. HashedRelation is requested for a concrete HashedRelation (and <> factory method is used)

. LongHashedRelation is requested for a <> (when BroadcastHashJoinExec is requested to BroadcastHashJoinExec.md#doExecute[execute])

=== [[writeExternal]] writeExternal Method

[source, scala]

writeExternal(out: ObjectOutput): Unit

NOTE: writeExternal is part of Java's ++https://docs.oracle.com/javase/8/docs/api/java/io/Externalizable.html#writeExternal-java.io.ObjectOutput-++[Externalizable Contract] to...FIXME.

writeExternal...FIXME

NOTE: writeExternal is used when...FIXME

=== [[readExternal]] readExternal Method

[source, scala]

readExternal(in: ObjectInput): Unit

NOTE: readExternal is part of Java's ++https://docs.oracle.com/javase/8/docs/api/java/io/Externalizable.html#readExternal-java.io.ObjectInput-++[Externalizable Contract] to...FIXME.

readExternal...FIXME

NOTE: readExternal is used when...FIXME

=== [[creating-instance]] Creating LongHashedRelation Instance

LongHashedRelation takes the following when created:

  • [[nFields]] Number of fields
  • [[map]] LongToUnsafeRowMap

LongHashedRelation initializes the <>.

=== [[asReadOnlyCopy]] Creating Read-Only Copy of LongHashedRelation -- asReadOnlyCopy Method

[source, scala]

asReadOnlyCopy(): LongHashedRelation

asReadOnlyCopy...FIXME

asReadOnlyCopy is part of the HashedRelation abstraction.

=== [[getValue]] Getting Value Row for Given Key -- getValue Method

[source, scala]

getValue(key: InternalRow): InternalRow

getValue checks if the input key is null at 0 position and if so gives null. Otherwise, getValue takes the long value at position 0 and <>.

getValue is part of the HashedRelation abstraction.

=== [[apply]] Creating LongHashedRelation Instance -- apply Factory Method

[source, scala]

apply( input: Iterator[InternalRow], key: Seq[Expression], sizeEstimate: Int, taskMemoryManager: TaskMemoryManager): LongHashedRelation


apply...FIXME

apply is used when HashedRelation is requested for a concrete HashedRelation.


Last update: 2020-11-07