BIG DATA & HADOOP Interview Question  Question: What is MapReduce in Hadoop Ans: Ø MapReduce is a processing technique and a program model for distributed computing based on java. Ø The MapReduce algorithm contains two important tasks, namely Map and Reduce. Ø Map takes a set of data and converts it into another set of data, where individual elements are broken down into tuples (key/value pairs) Q>What is MapReduce Shuffling and Sorting in Hadoop. Ans: Ø Shuffling is the process by which it transfers mappers intermediate output to the reducer. Ø Reducer gets 1 or more keys and associated values on the basis of reducers. Ø The intermediated key – value generated by mapper is sorted automatically by key. In Sort phase merging and sorting of map output takes place. Ø Shuffling and Sorting in Hadoop occurs simultaneously. #bigdatatechnologies   #hadoopdeveloper   #datacleaning   #dataanalytics   #learndatascience   #learningeveryday Question>How ...

Statistics Interview Question: Q2>LOG NORMAL DISTRIBUTION VS STANDARD NORMAL DISTRIBUTION:  The major difference is in its shape: the normal distribution is symmetrical, whereas the lognormal distribution is not. Because the values in a lognormal distribution are positive, they create a right-skewed curve. ... A further distinction is that the values used to derive a lognormal distribution are normally distributed   Q3>What are statistics? Ans: Statistics is a science of acquiring, classifying, organizing, analyzing, interpreting, and presenting numerical data so as to make inferences about the population from the sample drawn. Q4>Descriptive statistics? Ans: Descriptive statistics is that part of statistics that quantitatively describes the characteristics of a particular dataset under study, with the help of brief summary about the sample. Q5>What is Inferential Statistics? Ans: It is one of the types of statistics in which a random sample is drawn from a la...

Permission vs Role  in Tableau server Users = Each individual accessing the system must be setup as a user. This is similar to a user account for logging into your computer. Groups = A group is a way to organize similar users and grant them identical permissions. Site Role = This is a system definition that represents the maximum amount of permissions for a user. That means a user defined with a site role of Interactor can never publish content. A highly detailed walk through of each role is available here. In short, in decreasing order of power are: Server Administrator, Site Administrator, Publisher, Interactor, Viewer, Viewer (can publish), Unlicensed (can publish), Unlicensed. Permissions Rules = These out of the box configurations are available for selection when assigning permissions to content. Examples are Project Lead and Interactor. When selected, a default set of capabilities are provided. Permission Capabilities = This is the...