Apache Pig Interview Questions and Answers

Apache Pig is a platform for creating programs that run on Apache Hadoop. It uses the Pig Latin language. It also executes its Hadoop jobs in MapReduce, Apache Tez, or Apache Spark.

The difference between Apache Pig and Hadoop are as follows:

BloomMapFile in Apache Pig is a class that is used to provide a quick membership test for the keys using dynamic bloom filters. It extends the MapFile class.

Pig Latin is a language used in Apache PIg.

Some inbuilt Eval Functions of Apache Pig is listed below:

• AVG
• BagToString
• BagToTuple
• Bloom
• CONCAT
• COUNT
• COUNT_STAR
• DIFF
• IsEmpty
• MAX
• MIN
• PluckTuple
• SIZE
• SUBTRACT
• SUM
• IN
• TOKENIZE

PigDump used to Stores data in UTF-8 format, while PigStorage is used to Loads and store data as structured text files.

Some major differences between Apache Pig and SQL are listed below:

Scalar/Primitive Types specify the type of data that a variable can contain. Generally, It consists of predefined data types.

• Int
• Long
• Float
• Double
• Chararray
• Bytearray
• Boolean
• Datetime
• Biginteger

The three different execution modes are defined below:

Interactive Mode (Grunt shell) in Apache Pig includes the Grunt shell in which users can enter the Pig Latin statements and get the output (using Dump operator).

Batch Mode (Script) in Apache Pig allows writing the Pig Latin script in a single file with .pig extension.

Embedded Mode (UDF) in Apache Pig has the provision of defining User Defined Functions in programming languages such as Java and using them in our script

Grunt shell is a shell of Apache pig to write commands that uses pig Latin scripts.

Some Relational Operators available in PIg language is listed below:

• LOAD:
• FOREACH:
• FOREACH Result:
• FILTER:
• FILTER Result:
• JOIN:
• JOIN Result:
• ORDER BY:

The four data models in Apache Pig are listed below:

• Atom is an atomic data value that is used to store as a string.
• The tuple is an ordered set of the fields.
• The bag is a collection of tuples.
• The map is a set of key/value pairs.

In Apache Pig, Dynamic Invokers can be used to call a built-in static Java function that accepts a combination of strings, ints, longs, doubles, floats, or arrays, sometimes no arguments.

Some utility commands available in Apache Pig are listed below:

• Clear Command.
• Help Command.
• History Command.
• Set command.
• exec command.
• Kill Command.
• Run command.
• Quit Command.

An admin feature provides the ability to blacklist or/and whitelist certain commands and operations that could be not very safe in a multitenant environment.

Blacklisting assigns "pig.blacklist" to a comma-delimited set of operators and commands. For instance, pig.blacklist=rm,killcross would disable users from executing any of "rm", "kill" commands and "cross" operator.

Whitelist disables all commands and operators that are not a safer part of the whitelist environment. For instance, pig.whitelist=load,filter,store will disallow every command and operator other than "load", "filter" and "store".

Four Diagnostic operators available in Apache Pig are listed below:

• Dump operator.
• Describe operator.
• Explain the operator.
• Illustration operator.