io.lettuce.core.search.aggregateutils

Class Reducers

java.lang.Object

io.lettuce.core.search.aggregateutils.Reducers

@Experimental
public final class Reducers
extends Object

Factory class for creating Reducer instances.

Example usage:

 
 // Count items in each group
 Reducers.count().as("item_count")

 // Sum numeric values
 Reducers.sum("@sales").as("total_sales")

 // Calculate average
 Reducers.avg("@price").as("average_price")

 // Quantile with percentile parameter
 Reducers.quantile("@price", 0.5).as("median_price")

 // First value with optional sort by
 Reducers.firstValue("@name").by("@timestamp").as("first_name")

 // Random sample
 Reducers.randomSample("@id", 10).as("sample_ids")
 
 

Since:

7.5

Author:

Aleksandar Todorov

See Also:

Reducer, ReduceFunction

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Reducers.Avg
static class	Reducers.Count
static class	Reducers.CountDistinct
static class	Reducers.CountDistinctish
static class	Reducers.FirstValue
static class	Reducers.Max
static class	Reducers.Min
static class	Reducers.Quantile
static class	Reducers.RandomSample
static class	Reducers.Stddev
static class	Reducers.Sum
static class	Reducers.ToList

Method Summary

Modifier and Type	Method and Description
static Reducers.Avg	avg(String field)
static Reducers.Count	count()
static Reducers.CountDistinct	countDistinct(String field)
static Reducers.CountDistinctish	countDistinctish(String field)
static Reducers.FirstValue	firstValue(String field)
static Reducers.Max	max(String field)
static Reducers.Min	min(String field)
static Reducers.Quantile	quantile(String field, double quantile)
static Reducers.RandomSample	randomSample(String field, int sampleSize)
static Reducers.Stddev	stddev(String field)
static Reducers.Sum	sum(String field)
static Reducers.ToList	toList(String field)

Methods inherited from class java.lang.Object

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

Method Detail

count

public static Reducers.Count count()

countDistinct

public static Reducers.CountDistinct countDistinct(String field)

countDistinctish

public static Reducers.CountDistinctish countDistinctish(String field)

sum

public static Reducers.Sum sum(String field)

avg

public static Reducers.Avg avg(String field)

min

public static Reducers.Min min(String field)

max

public static Reducers.Max max(String field)

stddev

public static Reducers.Stddev stddev(String field)

quantile

public static Reducers.Quantile quantile(String field,
                                         double quantile)

toList

public static Reducers.ToList toList(String field)

firstValue

public static Reducers.FirstValue firstValue(String field)

randomSample

public static Reducers.RandomSample randomSample(String field,
                                                 int sampleSize)