Enum Class AggregateFunction

java.lang.Object

java.lang.Enum<AggregateFunction>

io.krabka.streams.columnar.AggregateFunction

All Implemented Interfaces:

Serializable, Comparable<AggregateFunction>, Constable

public enum AggregateFunction
extends Enum<AggregateFunction>

Built-in within-batch aggregate functions.

Used inside an Aggregation passed to BuiltinOp.groupBy(org.apache.arrow.memory.BufferAllocator, java.util.Collection, Aggregation...) or a windowed variant. Integral accumulation is exact and overflow-checked; an overflow throws ArithmeticException rather than wrapping.

Example

var totals = BuiltinOp.groupBy(
    allocator,
    List.of("user"),
    new Aggregation("amount", "total", AggregateFunction.SUM),
    new Aggregation("amount", "count", AggregateFunction.COUNT));

Nested Class Summary

Nested classes/interfaces inherited from class Enum

Enum.EnumDesc<E>

Enum Constant Summary

Enum Constants

Enum Constant	Description
COUNT	Counts the rows in the group, nulls included.
MAX	Keeps the largest non-null input value, compared with Comparable.
MIN	Keeps the smallest non-null input value, compared with Comparable.
SUM	Sums the non-null input values.

Method Summary

Modifier and Type	Method	Description
static AggregateFunction	valueOf(String name)	Returns the enum constant of this class with the specified name.
static AggregateFunction[]	values()	Returns an array containing the constants of this enum class, in the order they are declared.

Methods inherited from class Enum

clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

COUNT

public static final AggregateFunction COUNT

Counts the rows in the group, nulls included. The output column is a signed 64-bit integer unless the aggregation declares another type.

SUM

public static final AggregateFunction SUM

Sums the non-null input values. Integral inputs accumulate exactly, floating point inputs as double, and decimal inputs as BigDecimal. An all-null group yields null. The output keeps the input column's type unless the aggregation declares another type.

MIN

public static final AggregateFunction MIN

Keeps the smallest non-null input value, compared with Comparable. An all-null group yields null.

MAX

public static final AggregateFunction MAX

Keeps the largest non-null input value, compared with Comparable. An all-null group yields null.

Method Details

values

public static AggregateFunction[] values()

Returns an array containing the constants of this enum class, in the order they are declared.

Returns:

an array containing the constants of this enum class, in the order they are declared

valueOf

public static AggregateFunction valueOf(String name)

Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum class has no constant with the specified name

NullPointerException - if the argument is null