Apache Impala vs Pig: What are the differences?

Key Differences between Apache Impala and Pig

Apache Impala and Pig are both popular tools used for data processing in the big data ecosystem. While they serve similar purposes, there are several key differences between the two.

1. Syntax: Pig uses a high-level scripting language called Pig Latin, which is similar to SQL but also incorporates data processing functions. On the other hand, Impala uses a SQL-like syntax that provides a more familiar interface for SQL users.

2. Execution: Pig is an interpreted language that runs on top of the Hadoop framework, which means it can be slower compared to Impala. Impala, on the other hand, is a distributed SQL engine that can provide faster query execution by bypassing the Hadoop MapReduce layer.

3. Data Storage: Pig is typically used for processing data stored in Hadoop Distributed File System (HDFS), but it can also work with other storage systems. Impala is designed specifically for querying data stored in Hadoop distributed file systems like HDFS or Apache HBase.

4. Schema Definition: Pig is schema-on-read, which means it does not enforce strict data schemas. It can handle semi-structured or unstructured data formats. Impala, on the other hand, is schema-on-write, which requires a predefined schema for the data before it is stored.

5. Data Types: Pig supports a wide range of data types, including complex data types like maps and tuples. Impala also supports various data types but has a more limited range compared to Pig.

6. User Interface: Pig provides a command-line interface (CLI) where users can write Pig Latin scripts and interact with the data. Impala, on the other hand, provides a web-based user interface (UI) that allows users to write and run queries without the need for a separate CLI.

In summary, Apache Impala and Pig differ in terms of syntax, execution model, data storage, schema definition, data types, and user interface. Impala offers faster query execution with a more SQL-like syntax, while Pig provides flexibility with its high-level scripting language.