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

Resolving AWT saturation


AWTs are the smallest unit of work in Teradata. These are the tasks or execution threads inside of each AMP that get the database work done, such as executing a query step once the step is dispatched to the AMP. Each AMP has up to 80 AMP worker tasks available to them. AWTs can be increased from 80 if required, based on requirements and the size of the system.

Each request executing on a system may require more than 1 AWT to complete. Utilities tend to use more AWT per AMP because of their design. For example, a Fastload needs 3 AMP worker tasks in the first phase and one AMP worker task in the second phase. 

AWT, are very critical and are always in demand, below is the break up of 80 AMP worker tasks:

  • 24 AWTs are reserved for a special purpose
  • 56 AWTs are general purpose
  • A maximum of 50 AWTs can be used for Dispatched steps
  • The normal case is 62 AWTs used for Dispatched steps and the first level of spawned work

It is important to understand what happens when AMP worker...