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

Managing the FSG cache


With increasing need for faster responses of queries, Teradata Database has come up with many ways to cater to this need. The file segment cache, FSG subsystem, manages database files. It is the memory that is managed by PDE. The Teradata file system, FSYS, uses FSG services to access database segments on disk. AMPs are the basic entity that consumes the FSG cache as part of database segments residing in memory.

Understand FSG cache as a simple cache mechanism that stores parts of data rows in memory so AMPs, when reading data, do not have to go to the physical disk but can read rows from the memory itself. As we know, reading from memory is way faster than from the physical disk.

FSG provides an interface that allows the FSYS logic to merely access and release segments in memory. FSG takes care of the details of getting the data to and from permanent disk storage.

The FSG subsystem handles low-level database disk access. It typically manages database disks as raw devices...