What is Apache Pig?
Apache Pig is a tool that reduces the complexity of writing a MapReduce program. It is used to analyze large data sets and represent them as data flows. These large data sets consist of a high-level language for expressing data analysis programs. All data manipulation operations are carried out with Hadoop.
Pig Latin is a high-level language provided by Apache Pig for writing data analysis programs. This high-level language also provides methods for writing, reading, and processing data in data analysis programs.
Pig Latin scripts are converted into Map and Reduce tasks with the aid of a component in Pig called Pig Engine.
Components of Apache Pig
The components of Apache Pig that process the Pig Latin language through multiple layers are:
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Parser: The parser accepts a program submitted by the user and performs a syntax check and type check. The output of this operation is a
DAGthat contains Pig Latin statements and logical operators. -
Optimizer: This step pushes the
DAGto a logical optimizer for logical optimization. -
Compiler: This is the compilation step where the optimized logical plan is compiled into
MapReducejobs. -
Execution Engine: In this final step, the
MapReducejobs are submitted to Hadoop for execution. The desired data is sent to the user on completion.
Why use Apache Pig?
- Apache Pig is easy to learn due to its similarity to SQL.
- With Apache Pig, data operations such as
joins,filter,orderingetc. can be carried out easily. - It provides support for nested data types like tuples and maps that are not found in
MapReduce. - It uses a multi-query approach that reduces the lines of code needed for an operation.
Apache Pig features
Apache Pig has the following features:
-
It is extensible. Users can create their own functions for special-purpose processing like reading and writing data.
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It supports a large range of data types and analyzes all kinds of data, both structured and unstructured.
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It provides support for user-defined functions where users can create functions in other programming languages such as Java.
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It supports automatic optimization so the users only need to focus only on the semantics of the language.