What is reduce action in Spark

+1 vote

Can anyone explain how reduce() function works in Spark?

Jul 2, 2019 in Apache Spark by amrita

recategorized Jul 4, 2019 by Gitika 5,227 views

1 answer to this question.

+1 vote

Hey,

It takes a function that operates on two elements of the type in your RDD and returns a new element of the same type. A simple example of such a function is +, which we can use to sum our RDD.

 With reduce(), we can easily sum the elements of our RDD, count the number of elements, and perform other types of aggregations.

answered Jul 2, 2019 by Gitika
• 65,910 points
Can you explain in brief like, for the following example of code

rdd = sc.parallelize([1,2,3,4])

rdd.reduce(lambda a, b: a + b)

Can you explain in which way reduce performs sum operation according to below options.

option 1 - (1+2)+3)+4

option 2 - (1+2)+(3+4)
It happens as option 1

Related Questions In Apache Spark

+1 vote
1 answer

Can anyone explain what is RDD in Spark?

RDD is a fundamental data structure of ...READ MORE

answered May 24, 2018 in Apache Spark by Shubham
• 13,490 points
2,390 views
0 votes
1 answer

Spark 2.3? What is new in it?

Here are the changes in new version ...READ MORE

answered May 28, 2018 in Apache Spark by kurt_cobain
• 9,390 points
631 views
+1 vote
3 answers

What is the difference between rdd and dataframes in Apache Spark ?

Comparison between Spark RDD vs DataFrame 1. Release ...READ MORE

answered Aug 28, 2018 in Apache Spark by shams
• 3,670 points
42,318 views
0 votes
1 answer

What is Executor Memory in a Spark application?

Every spark application has same fixed heap ...READ MORE

answered Jan 5, 2019 in Apache Spark by Frankie
• 9,830 points
6,169 views
+1 vote
2 answers
+1 vote
1 answer

Hadoop Mapreduce word count Program

Firstly you need to understand the concept ...READ MORE

answered Mar 16, 2018 in Data Analytics by nitinrawat895
• 11,380 points
10,558 views
0 votes
1 answer

hadoop.mapred vs hadoop.mapreduce?

org.apache.hadoop.mapred is the Old API  org.apache.hadoop.mapreduce is the ...READ MORE

answered Mar 16, 2018 in Data Analytics by nitinrawat895
• 11,380 points
2,185 views
+2 votes
11 answers

hadoop fs -put command?

Hi, You can create one directory in HDFS ...READ MORE

answered Mar 16, 2018 in Big Data Hadoop by nitinrawat895
• 11,380 points
104,215 views
0 votes
1 answer

What is Action in Spark?

Hi, Actions are RDD’s operation, that value returns ...READ MORE

answered Jul 3, 2019 in Apache Spark by Gitika
• 65,910 points
11,245 views
0 votes
1 answer

What does reduce action do in Spark?

Hey, Reduce action converts an RDD to a ...READ MORE

answered Jul 4, 2019 in Apache Spark by Gitika
• 65,910 points
457 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP