Pig is a scripting language used for data analysis on Apache Hadoop. Pig scripts describe data flows and can perform all necessary data manipulations on Hadoop. Pig also allows integration with other languages through User Defined Functions. The document then provides steps to upload sample baseball data files to Hue and write a Pig Latin script to load, filter, group, and join the data to find the maximum runs scored by players each year.

1. Pig is a high level scripting language that is used with Apache Hadoop. Pig excels at
describing data analysis problems as data flows. Pig is complete in that you can do all the
required data manipulations in Apache Hadoop with Pig. In addition through the User
Defined Functions(UDF) facility in Pig you can have Pig invoke code in many languages like
JRuby, Jython and Java. Conversely you can execute Pig scripts in other languages. The result
is that you can use Pig as a component to build larger and more complex applications that
tackle real business problems.
Pig scripts are translated into a series of MapReduce jobs that are run on the Apache
Hadoop cluster. As part of the translation the Pig interpreter does perform optimizations to
speed execution on Apache Hadoop. We are going to write a Pig script that will do our data
analysis task.
Lets solve a simple exercise on how to run a pig script on hadoop platform:
Data Downloading
You can download the data file in csv zip form from:
http://hortonassets.s3.amazonaws.com/pig/lahman591-csv.zip
Once you have the file you will need to unzip the file into a directory. We will be uploading
just the master.csv and batting.csv files.
Uploading of the data
Although the link from where we are solving the program is an easy guide. We would be
using the hue to upload the files for execution of the program.
Steps to upload
a) Start VM Box and open SSH Terminal
b) Log on to the address http://127.0.0.1:8000/
c) Click on file browser option followed by view then click on hue
d) Upload 2 files batting.csv and master.csv.

2. Screenshot is attached below
Write the pig script and execute the program
Click on the pig icon on the header and a new script will open. Name this script as any name.
Here it is T2 and Code is written in the notepad type file.
Code:
load 'Batting.csv' using PigStorage(',');

3. This line will load the file Batting.Csv.Through pig storage we are passing the comma as the
delimiter
Raw runs = FILTER batting BY $1>0;
To filter the row the fist line would be used
runs = FOREACH raw runs GENERATE $0 as playerID , $1 as year , $8 as runs;
Foreach would iterate through batting data object. Generate pulls out selected fields and
assigns name,
grp_data = GROUP runs by (year);
This line would group runs by year.
max_runs = FOREACH grp_data GENERATE group as grp,MAX(runs.runs) as max_runs;
This line would find out the maximum runs
join_max_run = JOIN max_runs by ($0, max_runs), runs by (year,runs);
join_data = FOREACH join_max_run GENERATE $0 as year, $2 as
playerID, $1 as runs;
DUMP join_data;
We are combining and generating the dataset year, player id and maximum runs and
dumping the output to the screen
Click on the save and execute to compile the program and run
You can check the progress in the Job Browser Window.
This would take around 10-15 Minutes to work around.
Output