org.apache.beam.sdk.transforms

Class Sets

java.lang.Object

org.apache.beam.sdk.transforms.Sets

public class Sets
extends java.lang.Object

The PTransforms that allow to compute different set functions across PCollections.

They come in two variants. 1. Between two PCollection 2. Between two or more PCollection in a PCollectionList.

Following PTransforms follows SET DISTINCT semantics: intersectDistinct, expectDistinct, unionDistinct

Following PTransforms follows SET ALL semantics: intersectAll, expectAll, unionAll

For example, the following demonstrates intersectDistinct between two collections PCollections.

 Pipeline p = ...;

 PCollection<String> left = p.apply(Create.of("1", "2", "3", "3", "4", "5"));
 PCollection<String> right = p.apply(Create.of("1", "3", "4", "4", "6"));

 PCollection<String> results =
     left.apply(SetFns.intersectDistinct(right)); // results will be PCollection<String> containing: "1","3","4"

 

For example, the following demonstrates intersectDistinct between three collections PCollections in a PCollectionList.

 Pipeline p = ...;

 PCollection<String> first = p.apply(Create.of("1", "2", "3", "3", "4", "5"));
 PCollection<String> second = p.apply(Create.of("1", "3", "4", "4", "6"));
 PCollection<String> third = p.apply(Create.of("3", "4", "4"));

 // Following example will perform (first intersect second) intersect third.
 PCollection<String> results =
     PCollectionList.of(first).and(second).and(third)
     .apply(SetFns.intersectDistinct()); // results will be PCollection<String> containing: "3","4"

 

Constructor Summary

Constructors

Constructor and Description
Sets()

Method Summary

Modifier and Type	Method and Description
static <T> PTransform<PCollectionList<T>,PCollection<T>>	exceptAll() Returns a new PTransform transform that follows SET ALL semantics which takes a PCollectionList<PCollection<T>> and returns a PCollection<T> containing the difference all (exceptAll) of collections done in order for all collections in PCollectionList<T>.
static <T> PTransform<PCollection<T>,PCollection<T>>	exceptAll(PCollection<T> rightCollection) Returns a new PTransform transform that follows SET ALL semantics to compute the difference all (exceptAll) with provided PCollection<T>.
static <T> PTransform<PCollectionList<T>,PCollection<T>>	exceptDistinct() Returns a PTransform that takes a PCollectionList<PCollection<T>> and returns a PCollection<T> containing the difference (except) of collections done in order for all collections in PCollectionList<T>.
static <T> PTransform<PCollection<T>,PCollection<T>>	exceptDistinct(PCollection<T> rightCollection) Returns a new PTransform transform that follows SET DISTINCT semantics to compute the difference (except) with provided PCollection<T>.
static <T> PTransform<PCollectionList<T>,PCollection<T>>	intersectAll() Returns a new PTransform transform that follows SET ALL semantics which takes a PCollectionList<PCollection<T>> and returns a PCollection<T> containing the intersection all of collections done in order for all collections in PCollectionList<T>.
static <T> PTransform<PCollection<T>,PCollection<T>>	intersectAll(PCollection<T> rightCollection) Returns a new PTransform transform that follows SET ALL semantics to compute the intersection with provided PCollection<T>.
static <T> PTransform<PCollectionList<T>,PCollection<T>>	intersectDistinct() Returns a PTransform that takes a PCollectionList<PCollection<T>> and returns a PCollection<T> containing the intersection of collections done in order for all collections in PCollectionList<T>.
static <T> PTransform<PCollection<T>,PCollection<T>>	intersectDistinct(PCollection<T> rightCollection) Returns a new PTransform transform that follows SET DISTINCT semantics to compute the intersection with provided PCollection<T>.
static <T> Flatten.PCollections<T>	unionAll() Returns a new PTransform transform that follows SET ALL semantics which takes a PCollectionList<PCollection<T>> and returns a PCollection<T> containing the unionAll of collections done in order for all collections in PCollectionList<T>.
static <T> PTransform<PCollection<T>,PCollection<T>>	unionAll(PCollection<T> rightCollection) Returns a new PTransform transform that follows SET ALL semantics to compute the unionAll with provided PCollection<T>.
static <T> PTransform<PCollectionList<T>,PCollection<T>>	unionDistinct() Returns a new PTransform transform that follows SET DISTINCT semantics which takes a PCollectionList<PCollection<T>> and returns a PCollection<T> containing the union of collections done in order for all collections in PCollectionList<T>.
static <T> PTransform<PCollection<T>,PCollection<T>>	unionDistinct(PCollection<T> rightCollection) Returns a new PTransform transform that follows SET DISTINCT semantics to compute the union with provided PCollection<T>.

Methods inherited from class java.lang.Object

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

Constructor Detail

Sets

public Sets()

Method Detail

intersectDistinct

public static <T> PTransform<PCollection<T>,PCollection<T>> intersectDistinct(PCollection<T> rightCollection)

Returns a new PTransform transform that follows SET DISTINCT semantics to compute the intersection with provided PCollection<T>.

The argument should not be modified after this is called.

The elements of the output PCollection will all distinct elements that present in both pipeline is constructed and provided PCollection.

Note that this transform requires that the Coder of the all PCollection<T> to be deterministic (see Coder.verifyDeterministic()). If the collection Coder is not deterministic, an exception is thrown at pipeline construction time.

All inputs must have equal WindowFns and compatible triggers (see Trigger.isCompatible(Trigger)). Triggers with multiple firings may lead to nondeterministic results since the this PTransform is only computed over each individual firing.

By default, the output PCollection<T> encodes its elements using the same Coder as that of the input PCollection<T>

 Pipeline p = ...;

 PCollection<String> left = p.apply(Create.of("1", "2", "3", "3", "4", "5"));
 PCollection<String> right = p.apply(Create.of("1", "3", "4", "4", "6"));

 PCollection<String> results =
     left.apply(SetFns.intersectDistinct(right)); // results will be PCollection<String> containing: "1","3","4"

 

Type Parameters:

T - the type of the elements in the input and output PCollection<T>s.

intersectDistinct

public static <T> PTransform<PCollectionList<T>,PCollection<T>> intersectDistinct()

Returns a PTransform that takes a PCollectionList<PCollection<T>> and returns a PCollection<T> containing the intersection of collections done in order for all collections in PCollectionList<T>.

Returns a new PTransform transform that follows SET DISTINCT semantics which takes a PCollectionList<PCollection<T>> and returns a PCollection<T> containing the intersection of collections done in order for all collections in PCollectionList<T>.

The elements of the output PCollection will have all distinct elements that are present in both pipeline is constructed and next PCollection in the list and applied to all collections in order.

Note that this transform requires that the Coder of the all PCollection<T> to be deterministic (see Coder.verifyDeterministic()). If the collection Coder is not deterministic, an exception is thrown at pipeline construction time.

All inputs must have equal WindowFns and compatible triggers (see Trigger.isCompatible(Trigger)).Triggers with multiple firings may lead to nondeterministic results since the this PTransform is only computed over each individual firing.

By default, the output PCollection<T> encodes its elements using the same Coder as that of the first PCollection<T> in PCollectionList<T>.

 Pipeline p = ...;

 PCollection<String> first = p.apply(Create.of("1", "2", "3", "3", "4", "5"));
 PCollection<String> second = p.apply(Create.of("1", "3", "4", "4", "6"));
 PCollection<String> third = p.apply(Create.of("3", "4", "4"));

 // Following example will perform (first intersect second) intersect third.
 PCollection<String> results =
     PCollectionList.of(first).and(second).and(third)
     .apply(SetFns.intersectDistinct()); // results will be PCollection<String> containing: "3","4"

 

Type Parameters:

T - the type of the elements in the input PCollectionList<T> and output PCollection<T>s.

intersectAll

public static <T> PTransform<PCollection<T>,PCollection<T>> intersectAll(PCollection<T> rightCollection)

Returns a new PTransform transform that follows SET ALL semantics to compute the intersection with provided PCollection<T>.

The argument should not be modified after this is called.

The elements of the output PCollection which will follow INTESECT_ALL Semantics as follows: Given there are m elements on pipeline which is constructed PCollection (left) and n elements on in provided PCollection (right): - it will output MIN(m - n, 0) elements of left for all elements which are present in both left and right.

Note that this transform requires that the Coder of the all PCollection<T> to be deterministic (see Coder.verifyDeterministic()). If the collection Coder is not deterministic, an exception is thrown at pipeline construction time.

All inputs must have equal WindowFns and compatible triggers (see Trigger.isCompatible(Trigger)).Triggers with multiple firings may lead to nondeterministic results since the this PTransform is only computed over each individual firing.

By default, the output PCollection<T> encodes its elements using the same Coder as that of the input PCollection<T>

 Pipeline p = ...;

 PCollection<String> left = p.apply(Create.of("1", "1", "1", "2", "3", "3", "4", "5"));
 PCollection<String> right = p.apply(Create.of("1", "1", "3", "4", "4", "6"));

 PCollection<String> results =
     left.apply(SetFns.intersectAll(right)); // results will be PCollection<String> containing: "1","1","3","4"
 

Type Parameters:

T - the type of the elements in the input and output PCollection<T>s.

intersectAll

public static <T> PTransform<PCollectionList<T>,PCollection<T>> intersectAll()

Returns a new PTransform transform that follows SET ALL semantics which takes a PCollectionList<PCollection<T>> and returns a PCollection<T> containing the intersection all of collections done in order for all collections in PCollectionList<T>.

The elements of the output PCollection which will follow INTERSECT_ALL semantics. Output is calculated as follows: Given there are m elements on pipeline which is constructed PCollection (left) and n elements on in provided PCollection (right): - it will output MIN(m - n, 0) elements of left for all elements which are present in both left and right.

Note that this transform requires that the Coder of the all PCollection<T> to be deterministic (see Coder.verifyDeterministic()). If the collection Coder is not deterministic, an exception is thrown at pipeline construction time.

All inputs must have equal WindowFns and compatible triggers (see Trigger.isCompatible(Trigger)).Triggers with multiple firings may lead to nondeterministic results since the this PTransform is only computed over each individual firing.

By default, the output PCollection<T> encodes its elements using the same Coder as that of the first PCollection<T> in PCollectionList<T>.

 Pipeline p = ...;
 PCollection<String> first = p.apply(Create.of("1", "1", "1", "2", "3", "3", "4", "5"));
 PCollection<String> second = p.apply(Create.of("1", "1", "3", "4", "4", "6"));
 PCollection<String> third = p.apply(Create.of("1", "5"));

 // Following example will perform (first intersect second) intersect third.
 PCollection<String> results =
     PCollectionList.of(first).and(second).and(third)
     .apply(SetFns.intersectAll()); // results will be PCollection<String> containing: "1"

 

Type Parameters:

T - the type of the elements in the input PCollectionList<T> and output PCollection<T>s.

exceptDistinct

public static <T> PTransform<PCollection<T>,PCollection<T>> exceptDistinct(PCollection<T> rightCollection)

Returns a new PTransform transform that follows SET DISTINCT semantics to compute the difference (except) with provided PCollection<T>.

The argument should not be modified after this is called.

The elements of the output PCollection will all distinct elements that present in pipeline is constructed but not present in provided PCollection.

Note that this transform requires that the Coder of the all PCollection<T> to be deterministic (see Coder.verifyDeterministic()). If the collection Coder is not deterministic, an exception is thrown at pipeline construction time.

All inputs must have equal WindowFns and compatible triggers (see Trigger.isCompatible(Trigger)).Triggers with multiple firings may lead to nondeterministic results since the this PTransform is only computed over each individual firing.

By default, the output PCollection<T> encodes its elements using the same Coder as that of the input PCollection<T>

 Pipeline p = ...;

 PCollection<String> left = p.apply(Create.of("1", "1", "1", "2", "3", "3","4", "5"));
 PCollection<String> right = p.apply(Create.of("1", "1", "3", "4", "4", "6"));

 PCollection<String> results =
     left.apply(SetFns.exceptDistinct(right)); // results will be PCollection<String> containing: "2","5"
 

Type Parameters:

T - the type of the elements in the input and output PCollection<T>s.

exceptDistinct

public static <T> PTransform<PCollectionList<T>,PCollection<T>> exceptDistinct()

Returns a PTransform that takes a PCollectionList<PCollection<T>> and returns a PCollection<T> containing the difference (except) of collections done in order for all collections in PCollectionList<T>.

Returns a new PTransform transform that follows SET DISTINCT semantics which takes a PCollectionList<PCollection<T>> and returns a PCollection<T> containing the difference (except) of collections done in order for all collections in PCollectionList<T>.

The elements of the output PCollection will have all distinct elements that are present in pipeline is constructed but not present in next PCollection in the list and applied to all collections in order.

Note that this transform requires that the Coder of the all PCollection<T> to be deterministic (see Coder.verifyDeterministic()). If the collection Coder is not deterministic, an exception is thrown at pipeline construction time.

All inputs must have equal WindowFns and compatible triggers (see Trigger.isCompatible(Trigger)).Triggers with multiple firings may lead to nondeterministic results since the this PTransform is only computed over each individual firing.

By default, the output PCollection<T> encodes its elements using the same Coder as that of the first PCollection<T> in PCollectionList<T>.

 Pipeline p = ...;
 PCollection<String> first = p.apply(Create.of("1", "1", "1", "2", "3", "3", "4", "5"));
 PCollection<String> second = p.apply(Create.of("1", "1", "3", "4", "4", "6"));

 PCollection<String> third = p.apply(Create.of("1", "2", "2"));

 // Following example will perform (first intersect second) intersect third.
 PCollection<String> results =
     PCollectionList.of(first).and(second).and(third)
     .apply(SetFns.exceptDistinct()); // results will be PCollection<String> containing: "5"

 

Type Parameters:

T - the type of the elements in the input PCollectionList<T> and output PCollection<T>s.

exceptAll

public static <T> PTransform<PCollection<T>,PCollection<T>> exceptAll(PCollection<T> rightCollection)

Returns a new PTransform transform that follows SET ALL semantics to compute the difference all (exceptAll) with provided PCollection<T>.

The argument should not be modified after this is called.

The elements of the output PCollection which will follow EXCEPT_ALL Semantics as follows: Given there are m elements on pipeline which is constructed PCollection (left) and n elements on in provided PCollection (right): - it will output m elements of left for all elements which are present in left but not in right. - it will output MAX(m - n, 0) elements of left for all elements which are present in both left and right.

Note that this transform requires that the Coder of the all PCollection<T> to be deterministic (see Coder.verifyDeterministic()). If the collection Coder is not deterministic, an exception is thrown at pipeline construction time.

All inputs must have equal WindowFns and compatible triggers (see Trigger.isCompatible(Trigger)).Triggers with multiple firings may lead to nondeterministic results since the this PTransform is only computed over each individual firing.

By default, the output PCollection<T> encodes its elements using the same Coder as that of the input PCollection<T>

 Pipeline p = ...;

 PCollection<String> left = p.apply(Create.of("1", "1", "1", "2", "3", "3", "3", "4", "5"));
 PCollection<String> right = p.apply(Create.of("1", "3", "4", "4", "6"));

 PCollection<String> results =
     left.apply(SetFns.exceptAll(right)); // results will be PCollection<String> containing: "1","1","2","3","3","5"
 

Type Parameters:

T - the type of the elements in the input and output PCollection<T>s.

exceptAll

public static <T> PTransform<PCollectionList<T>,PCollection<T>> exceptAll()

Returns a new PTransform transform that follows SET ALL semantics which takes a PCollectionList<PCollection<T>> and returns a PCollection<T> containing the difference all (exceptAll) of collections done in order for all collections in PCollectionList<T>.

The elements of the output PCollection which will follow EXCEPT_ALL semantics. Output is calculated as follows: Given there are m elements on pipeline which is constructed PCollection (left) and n elements on in provided PCollection (right): - it will output m elements of left for all elements which are present in left but not in right. - it will output MAX(m - n, 0) elements of left for all elements which are present in both left and right.

Note that this transform requires that the Coder of the all PCollection<T> to be deterministic (see Coder.verifyDeterministic()). If the collection Coder is not deterministic, an exception is thrown at pipeline construction time.

All inputs must have equal WindowFns and compatible triggers (see Trigger.isCompatible(Trigger)).Triggers with multiple firings may lead to nondeterministic results since the this PTransform is only computed over each individual firing.

By default, the output PCollection<T> encodes its elements using the same Coder as that of the first PCollection<T> in PCollectionList<T>.

 Pipeline p = ...;
 PCollection<String> first = p.apply(Create.of("1", "1", "1", "2", "3", "3", "3", "4", "5"));
 PCollection<String> second = p.apply(Create.of("1", "3", "4", "4", "6"));
 PCollection<String> third = p.apply(Create.of("1", "5"));

 // Following example will perform (first intersect second) intersect third.
 PCollection<String> results =
     PCollectionList.of(first).and(second).and(third)
     .apply(SetFns.exceptAll()); // results will be PCollection<String> containing: "1","2","3","3"

 

Type Parameters:

T - the type of the elements in the input PCollectionList<T> and output PCollection<T>s.

unionDistinct

public static <T> PTransform<PCollection<T>,PCollection<T>> unionDistinct(PCollection<T> rightCollection)

Returns a new PTransform transform that follows SET DISTINCT semantics to compute the union with provided PCollection<T>.

The argument should not be modified after this is called.

The elements of the output PCollection will all distinct elements that present in pipeline is constructed or present in provided PCollection.

Note that this transform requires that the Coder of the all PCollection<T> to be deterministic (see Coder.verifyDeterministic()). If the collection Coder is not deterministic, an exception is thrown at pipeline construction time.

All inputs must have equal WindowFns and compatible triggers (see Trigger.isCompatible(Trigger)).Triggers with multiple firings may lead to nondeterministic results since the this PTransform is only computed over each individual firing.

By default, the output PCollection<T> encodes its elements using the same Coder as that of the input PCollection<T>

 Pipeline p = ...;

 PCollection<String> left = p.apply(Create.of("1", "1", "2"));
 PCollection<String> right = p.apply(Create.of("1", "3", "4", "4"));

 PCollection<String> results =
     left.apply(SetFns.unionDistinct(right)); // results will be PCollection<String> containing: "1","2","3","4"
 

Type Parameters:

T - the type of the elements in the input and output PCollection<T>s.

unionDistinct

public static <T> PTransform<PCollectionList<T>,PCollection<T>> unionDistinct()

Returns a new PTransform transform that follows SET DISTINCT semantics which takes a PCollectionList<PCollection<T>> and returns a PCollection<T> containing the union of collections done in order for all collections in PCollectionList<T>.

The elements of the output PCollection will have all distinct elements that are present in pipeline is constructed or present in next PCollection in the list and applied to all collections in order.

Note that this transform requires that the Coder of the all PCollection<T> to be deterministic (see Coder.verifyDeterministic()). If the collection Coder is not deterministic, an exception is thrown at pipeline construction time.

All inputs must have equal WindowFns and compatible triggers (see Trigger.isCompatible(Trigger)).Triggers with multiple firings may lead to nondeterministic results since the this PTransform is only computed over each individual firing.

By default, the output PCollection<T> encodes its elements using the same Coder as that of the first PCollection<T> in PCollectionList<T>.

 Pipeline p = ...;
 PCollection<String> first = p.apply(Create.of("1", "1", "2"));
 PCollection<String> second = p.apply(Create.of("1", "3", "4", "4"));

 PCollection<String> third = p.apply(Create.of("1", "5"));

 // Following example will perform (first intersect second) intersect third.
 PCollection<String> results =
     PCollectionList.of(first).and(second).and(third)
     .apply(SetFns.unionDistinct()); // results will be PCollection<String> containing: "1","2","3","4","5"

 

Type Parameters:

T - the type of the elements in the input PCollectionList<T> and output PCollection<T>s.

unionAll

public static <T> PTransform<PCollection<T>,PCollection<T>> unionAll(PCollection<T> rightCollection)

Returns a new PTransform transform that follows SET ALL semantics to compute the unionAll with provided PCollection<T>.

The argument should not be modified after this is called.

The elements of the output PCollection which will follow UNION_ALL semantics as follows: Given there are m elements on pipeline which is constructed PCollection (left) and n elements on in provided PCollection (right): - it will output m elements of left and m elements of right.

Note that this transform requires that the Coder of the all PCollection<T> to be deterministic (see Coder.verifyDeterministic()). If the collection Coder is not deterministic, an exception is thrown at pipeline construction time.

All inputs must have equal WindowFns and compatible triggers (see Trigger.isCompatible(Trigger)).Triggers with multiple firings may lead to nondeterministic results since the this PTransform is only computed over each individual firing.

By default, the output PCollection<T> encodes its elements using the same Coder as that of the input PCollection<T>

 Pipeline p = ...;

 PCollection<String> left = p.apply(Create.of("1", "1", "2"));
 PCollection<String> right = p.apply(Create.of("1", "3", "4", "4"));

 PCollection<String> results =
     left.apply(SetFns.unionAll(right)); // results will be PCollection<String> containing: "1","1","1","2","3","4","4"
 

Type Parameters:

T - the type of the elements in the input and output PCollection<T>s.

unionAll

public static <T> Flatten.PCollections<T> unionAll()

Returns a new PTransform transform that follows SET ALL semantics which takes a PCollectionList<PCollection<T>> and returns a PCollection<T> containing the unionAll of collections done in order for all collections in PCollectionList<T>.

The elements of the output PCollection which will follow UNION_ALL semantics. Output is calculated as follows: Given there are m elements on pipeline which is constructed PCollection (left) and n elements on in provided PCollection (right): - it will output m elements of left and m elements of right.

Note that this transform requires that the Coder of the all inputs PCollection<T> to be deterministic (see Coder.verifyDeterministic()). If the collection Coder is not deterministic, an exception is thrown at pipeline construction time.

All inputs must have equal WindowFns and compatible triggers (see Trigger.isCompatible(Trigger)).Triggers with multiple firings may lead to nondeterministic results since the this PTransform is only computed over each individual firing.

By default, the output PCollection<T> encodes its elements using the same Coder as that of the first PCollection<T> in PCollectionList<T>.

 Pipeline p = ...;
 PCollection<String> first = p.apply(Create.of("1", "1", "2"));
 PCollection<String> second = p.apply(Create.of("1", "3", "4", "4"));
 PCollection<String> third = p.apply(Create.of("1", "5"));

 // Following example will perform (first intersect second) intersect third.
 PCollection<String> results =
     PCollectionList.of(first).and(second).and(third)
     .apply(SetFns.unionAll()); // results will be PCollection<String> containing: "1","1","1","1","2","3","4","4","5"

 

Type Parameters:

T - the type of the elements in the input PCollectionList<T> and output PCollection<T>s.