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

HCatalog


In this recipe, you will learn how you can define tables in HCatalog.

Getting ready

HCatalog is a storage management tool that enables frameworks other than Hive to leverage a data model to read and write data. HCatalog tables provide an abstraction on the data format in HDFS and allow frameworks such as PIG and MapReduce to use the data without being concerned about the data format, such as RC, ORC, and text files.

HCatInputFormat and HCatOutputFormat, which are the implementations of Hadoop InputFormat and OutputFormat, are the interfaces provided to PIG and MapReduce.

How to do it…

Data is defined using the HCatalog CLI. Data is modeled as tables and tables are stored in databases. The table could be partitioned based on keys.

HCatalog DMLs

The following are the metrics of DMLs supported by HCatalog:

Command

Support

Description

CREATE TABLE

Yes

Same as Hive, but if created with the CLUSTERED BY clause then write to table with PIG and MapReduce is not available

DROP TABLE

Yes

...