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

Dropping tables


In this recipe, you will learn how to drop a table in Hive.

Getting ready

DROP TABLE command removes the table from the database, including the data from the table. This is equivalent to the SQL DROP command, but the only difference is that the data is moved to the Trash folder in the home directory (if Trash is configured). If Trash is not configured, data is removed from the filesystem as well and is lost forever.

Note

In the case of an external table, data remains in the filesystem even if the table is dropped from the database.

The general format of using the DROP TABLE command is as follows:

DROP TABLE [IF EXISTS] table_name [PURGE];

Where:

  • [IF EXISTS]: Is an optional clause. If not used, an error is thrown when there is an attempt to drop a table that does not exist in the database.

  • [PURGE]: Is an optional clause. If specified, the data is not saved in the Trash folder under the home directory and is lost forever.

How to do it…

Follow these steps to drop a table in Hive:

  • The...