Book Image

Teradata Cookbook

By : Abhinav Khandelwal, Viswanath Kasi, Rajsekhar Bhamidipati
Book Image

Teradata Cookbook

By: Abhinav Khandelwal, Viswanath Kasi, Rajsekhar Bhamidipati

Overview of this book

Teradata is an enterprise software company that develops and sells its eponymous relational database management system (RDBMS), which is considered to be a leading data warehousing solutions and provides data management solutions for analytics. This book will help you get all the practical information you need for the creation and implementation of your data warehousing solution using Teradata. The book begins with recipes on quickly setting up a development environment so you can work with different types of data structuring and manipulation function. You will tackle all problems related to efficient querying, stored procedure searching, and navigation techniques. Additionally, you’ll master various administrative tasks such as user and security management, workload management, high availability, performance tuning, and monitoring. This book is designed to take you through the best practices of performing the real daily tasks of a Teradata DBA, and will help you tackle any problem you might encounter in the process.
Table of Contents (19 chapters)
Title Page
Dedication
Packt Upsell
Contributors
Preface
Index

Creating a join index to improve performance


A join index is a data structure that contains data from one or more tables, with or without aggregation:

  • The columns of two or more tables
  • Two or more columns of a single table

The guidelines for creating a join index are the same as those for defining any regular join query that is frequently executed or whose performance is critical. The only difference is that, for a join index, the join result is persistently stored and automatically maintained.

Join indexes are used in Teradata to:

  • Pre-join tables that are often joined in queries.
  • Pre-aggregate summary data.
  • Create materialized views of data. In Teradata, it is described as a link between view and index.
  • Create a sparse data set.

A join index helps in increasing the efficiency and performance of the queries containing joins:

  •  A join index is accessed repeatedly when called by queries
  •  A new join index sub-table is created and automatically updated when the base tables change
  • A join index can have a...