Book Image

Apache Hive Essentials. - Second Edition

By : Dayong Du
Book Image

Apache Hive Essentials. - Second Edition

By: Dayong Du

Overview of this book

In this book, we prepare you for your journey into big data by frstly introducing you to backgrounds in the big data domain, alongwith the process of setting up and getting familiar with your Hive working environment. Next, the book guides you through discovering and transforming the values of big data with the help of examples. It also hones your skills in using the Hive language in an effcient manner. Toward the end, the book focuses on advanced topics, such as performance, security, and extensions in Hive, which will guide you on exciting adventures on this worthwhile big data journey. By the end of the book, you will be familiar with Hive and able to work effeciently to find solutions to big data problems
Table of Contents (12 chapters)

Data optimization

Data file optimization covers the performance improvement on the data files in terms of file format, compression, and storage.

File format

Hive supports TEXTFILE, SEQUENCEFILE, AVRO, RCFILE, ORC, and PARQUET file formats. There are two HQL statements used to specify the file format as follows:

  • CREATE TABLE ... STORE AS <file_format>: Specify the file format when creating a table
  • ALTER TABLE ... [PARTITION partition_spec] SET FILEFORMAT <file_format>: Modify the file format (definition only) in an existing table

Once a table stored in text format is created, we can load text data directly into it. To load text data into tables that have other file formats, we can first load the data into a table...