Book Image

Apache Hive Cookbook

Book Image

Apache Hive Cookbook

Overview of this book

Hive was developed by Facebook and later open sourced in Apache community. Hive provides SQL like interface to run queries on Big Data frameworks. Hive provides SQL like syntax also called as HiveQL that includes all SQL capabilities like analytical functions which are the need of the hour in today’s Big Data world. This book provides you easy installation steps with different types of metastores supported by Hive. This book has simple and easy to learn recipes for configuring Hive clients and services. You would also learn different Hive optimizations including Partitions and Bucketing. The book also covers the source code explanation of latest Hive version. Hive Query Language is being used by other frameworks including spark. Towards the end you will cover integration of Hive with these frameworks.
Table of Contents (19 chapters)
Apache Hive Cookbook
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Index

Describing a database schema


In this recipe, you will learn how to describe databases in Hive.

Getting ready

The DESCRIBE DATABASE command is used to get information about the database, such as the name of the database, its comment (if attached during the creation of the database), its location on the filesystem, and its dbproperties. The general format of using the DESCRIBE DATABASE command is as follows:

DESCRIBE DATABASE [EXTENDED] db_name;
DESCRIBE SCHEMA [EXTENDED] db_name;

Where:

  • DATABASE|SCHEMA: These are the same thing. These words can be used interchangeably.

  • [EXTENDED]: This is an optional clause. This clause will list all the dbproperties attached to a particular database in Hive.

How to do it…

Follow these steps to describe a database in Hive:

  • The following example lists the name of the database, the comment on the database, and the directory location on the filesystem:

    Describe database Hive_learning;
    
  • The following example gives the same result as previous one:

    Describe schema Hive_learning...