org.apache.cassandra.db.aggregation

Class AggregationSpecification

java.lang.Object

org.apache.cassandra.db.aggregation.AggregationSpecification

public abstract class AggregationSpecification
extends java.lang.Object

Defines how rows should be grouped for creating aggregates.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AggregationSpecification.Kind The AggregationSpecification kinds.
static class	AggregationSpecification.Serializer

Field Summary

Fields

Modifier and Type	Field and Description
static AggregationSpecification	AGGREGATE_EVERYTHING AggregationSpecification that group all the row together.
static AggregationSpecification.Serializer	serializer

Method Summary

Modifier and Type	Method and Description
static AggregationSpecification	aggregatePkPrefix(ClusteringComparator comparator, int clusteringPrefixSize) Creates a new AggregationSpecification instance that will build aggregates based on primary key columns.
AggregationSpecification.Kind	kind() Returns the AggregationSpecification kind.
GroupMaker	newGroupMaker() Creates a new GroupMaker instance.
abstract GroupMaker	newGroupMaker(GroupingState state) Creates a new GroupMaker instance.

Methods inherited from class java.lang.Object

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

Field Detail

serializer

public static final AggregationSpecification.Serializer serializer

AGGREGATE_EVERYTHING

public static final AggregationSpecification AGGREGATE_EVERYTHING

AggregationSpecification that group all the row together.

Method Detail

kind

public AggregationSpecification.Kind kind()

Returns the AggregationSpecification kind.

Returns:

the AggregationSpecification kind

newGroupMaker

public final GroupMaker newGroupMaker()

Creates a new GroupMaker instance.

Returns:

a new GroupMaker instance

newGroupMaker

public abstract GroupMaker newGroupMaker(GroupingState state)

Creates a new GroupMaker instance.

Parameters:

state - GroupMaker state

Returns:

a new GroupMaker instance

aggregatePkPrefix

public static AggregationSpecification aggregatePkPrefix(ClusteringComparator comparator,
                                                         int clusteringPrefixSize)

Creates a new AggregationSpecification instance that will build aggregates based on primary key columns.

Parameters:

comparator - the comparator used to compare the clustering prefixes

clusteringPrefixSize - the number of clustering columns used to create the aggregates

Returns:

a new AggregationSpecification instance that will build aggregates based on primary key columns