Book Image

Mastering Hadoop

By : Sandeep Karanth
Book Image

Mastering Hadoop

By: Sandeep Karanth

Overview of this book

Table of Contents (21 chapters)
Mastering Hadoop
About the Author
About the Reviewers

Pig performance optimizations

In this section, we will look at different performance parameters and how to tune them for optimized Pig script execution.

The optimization rules

Pig applies optimization rules on the generated logical plan for a Pig script. By default, all rules are enabled. The pig.optimizer.rules.disabled property can be used to disable rules. The –optimizer_off command-line option can also be used when executing a Pig script to disable rules. Some rules are mandatory and cannot be disabled. The all option disables all the non-mandatory rules:

set pig.optimizer.rules.disabled <comma-separated rules list>

Alternatively, you can use the following command:

pig –t|–optimizer_off [rule name | all]


FilterLogicExpressionSimplifier is turned off by default. Setting the property pig.exec.filterLogicExpressionSimplifier to true can turn it on.

Most of the optimization rules discussed in the following section are simple and borrowed from database query optimizations:

  • PartitionFilterOptimizer...