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

Using Date/Time data types


Hive supports two data types for Date/Time-related fields—Timestamp and Date:

The Timestamp data type is used to represent a particular time with the date and time value. It supports variable-length encoding of the traditional UNIX timestamp with an optional nanosecond precision.

It supports different conversions. The timestamp value provided as an integer numeric type is interpreted as a UNIX timestamp in seconds; a timestamp value provided as a floating point numeric type is interpreted as a UNIX timestamp in seconds with decimal precision; the timestamp value provided as string is interpreted as the java.sql.Timestamp format YYYY-MM-DD HH:MM:SS.fffffffff.

If the timestamp value is in another format than yyyy-mm-dd hh:mm:ss[.f...], then UDF can be used to convert them to the timestamp format. The Date type is used to represent only the date part of timestamp, that is, YYYY-MM-DD. This type doesn't represent the time of day component. The Date ranges allowed are...