oracle.spatial.spark.vector.index.quadtree

Class QuadTreeDistIndex<T>

java.lang.Object

oracle.spatial.spark.vector.index.DistributedSpatialIndex<T>

oracle.spatial.spark.vector.index.quadtree.QuadTreeDistIndex<T>

Type Parameters:

T -

All Implemented Interfaces:

java.io.Serializable

public class QuadTreeDistIndex<T>
extends DistributedSpatialIndex<T>

An implementation of DistributedSpatialIndex based on a QuadTree

Author:

hsaucedo

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
QuadTreeDistIndex(java.lang.Class<T> type) Crates a new instance ready for an RDD of the given generic type

Method Summary

Modifier and Type	Method and Description
void	cache() Persist the index' internal RDD with the default storage level
SpatialJavaRDD<T>	filter(<any> filterFunc, SpatialOperationConfig spatialOpConf) Returns a new spatial RDD containing only the elements that satisfy both, the filtering function and the spatial operation
<R> <any>	flatMap(<any> f, SpatialOperationConfig spatialOpConf) Returns a new RDD by first spatially filtering the RDD elements using the spatial operation given by spatialOpConf, then a function is applied to all the remaining elements.
<T2,R> <any>	join(SpatialJavaRDD<T2> rdd2, <any> f, SpatialOperationConfig spatialOpConf) Joins the records of the current index' data set with another spatial data set based on a spatial relationship between both data set's records
java.util.List<<any>>	nearestNeighbors(<any> f, int k, SpatialOperationConfig spatialOpConf) Returns the k elements from the RDD which are closest to the query window defined in spatialOpConf
void	persist(StorageLevel storageLevel) Sets the index' internal RDD's storage level to persist its values across operations after the first time it is computed.
void	read(JavaSparkContext sc, java.lang.String file) Loads a persisted index from the given path.
void	unpersist() Marks the index' internal RDD as non-persistent
void	write(JavaSparkContext sc, java.lang.String pathStr) Writes the current index to the given path

Methods inherited from class oracle.spatial.spark.vector.index.DistributedSpatialIndex

createIndex, load, load, save

Methods inherited from class java.lang.Object

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

Constructor Detail

QuadTreeDistIndex

public QuadTreeDistIndex(java.lang.Class<T> type)

Crates a new instance ready for an RDD of the given generic type

Parameters:

type -

Method Detail

cache

public void cache()

Description copied from class: DistributedSpatialIndex

Persist the index' internal RDD with the default storage level

Specified by:

cache in class DistributedSpatialIndex<T>

filter

public SpatialJavaRDD<T> filter(<any> filterFunc,
                                SpatialOperationConfig spatialOpConf)
                         throws java.lang.Exception

Description copied from class: DistributedSpatialIndex

Returns a new spatial RDD containing only the elements that satisfy both, the filtering function and the spatial operation

Specified by:

filter in class DistributedSpatialIndex<T>

Parameters:

filterFunc - a filtering function

spatialOpConf - the spatial operation configuration to spatially filter the RDD

Returns:

a new SpatialJavaRDD

Throws:

java.lang.Exception

flatMap

public <R> <any> flatMap(<any> f,
                         SpatialOperationConfig spatialOpConf)
                  throws java.lang.Exception

Description copied from class: DistributedSpatialIndex

Returns a new RDD by first spatially filtering the RDD elements using the spatial operation given by spatialOpConf, then a function is applied to all the remaining elements.

Specified by:

flatMap in class DistributedSpatialIndex<T>

Parameters:

f - a function to apply to each element

spatialOpConf - the spatial operation configuration to spatially filter the RDD

Returns:

a new RDD

Throws:

java.lang.Exception

join

public <T2,R> <any> join(SpatialJavaRDD<T2> rdd2,
                         <any> f,
                         SpatialOperationConfig spatialOpConf)
                  throws java.lang.Exception

Description copied from class: DistributedSpatialIndex

Joins the records of the current index' data set with another spatial data set based on a spatial relationship between both data set's records

Specified by:

join in class DistributedSpatialIndex<T>

Parameters:

rdd2 - a spatial RDD to join with

f - a tuple processor function which receives a tuple of records from both data sets which match the spatial join condition

spatialOpConf - a spatial operation configuration defining the spatial relationship to join records

Returns:

a new RDD

Throws:

java.lang.Exception

nearestNeighbors

public java.util.List<<any>> nearestNeighbors(<any> f,
                                              int k,
                                              SpatialOperationConfig spatialOpConf)
                                       throws java.lang.Exception

Description copied from class: DistributedSpatialIndex

Returns the k elements from the RDD which are closest to the query window defined in spatialOpConf

Specified by:

nearestNeighbors in class DistributedSpatialIndex<T>

Parameters:

f - an optional filtering function which should return true for the elements which can be part of the solution

k - the number of nearest neighbors to return

spatialOpConf - a spatial configuration containing the query window to be used. SpatialOperation is ignored for this action.

Returns:

a list of tuples where each tuple contains a distance and a nearest neighbor

Throws:

java.lang.Exception

persist

public void persist(StorageLevel storageLevel)

Description copied from class: DistributedSpatialIndex

Sets the index' internal RDD's storage level to persist its values across operations after the first time it is computed.

Specified by:

persist in class DistributedSpatialIndex<T>

read

public void read(JavaSparkContext sc,
                 java.lang.String file)
          throws java.lang.Exception

Description copied from class: DistributedSpatialIndex

Loads a persisted index from the given path. The persisted index is expected to be of the same implementation class than the current instance

Specified by:

read in class DistributedSpatialIndex<T>

Parameters:

sc - an existing Spark context

file - a path on either, a local or distributed file system

Throws:

java.lang.Exception

unpersist

public void unpersist()

Description copied from class: DistributedSpatialIndex

Marks the index' internal RDD as non-persistent

Specified by:

unpersist in class DistributedSpatialIndex<T>

write

public void write(JavaSparkContext sc,
                  java.lang.String pathStr)
           throws java.lang.Exception

Description copied from class: DistributedSpatialIndex

Writes the current index to the given path

Specified by:

write in class DistributedSpatialIndex<T>

Parameters:

sc - an existing Spark context

pathStr - a path on either, a local or distributed file system

Throws:

java.lang.Exception