Book Image

Microsoft SQL Server 2012 Integration Services: An Expert Cookbook

Book Image

Microsoft SQL Server 2012 Integration Services: An Expert Cookbook

Overview of this book

SQL Server Integration Services (SSIS) is a leading tool in the data warehouse industry - used for performing extraction, transformation, and load operations. This book is aligned with the most common methodology associated with SSIS known as Extract Transform and Load (ETL); ETL is responsible for the extraction of data from several sources, their cleansing, customization, and loading into a central repository normally called Data Warehouse or Data Mart.Microsoft SQL Server 2012 Integration Services: An Expert Cookbook covers all the aspects of SSIS 2012 with lots of real-world scenarios to help readers understand usages of SSIS in every environment. Written by two SQL Server MVPs who have in-depth knowledge of SSIS having worked with it for many years.This book starts by creating simple data transfer packages with wizards and illustrates how to create more complex data transfer packages, troubleshoot packages, make robust SSIS packages, and how to boost the performance of data consolidation with SSIS. It then covers data flow transformations and advanced transformations for data cleansing, fuzzy and term extraction in detail. The book then dives deep into making a dynamic package with the help of expressions and variables, and performance tuning and consideration.
Table of Contents (23 chapters)
Microsoft SQL Server 2012 Integration Services: An Expert Cookbook
Credits
Foreword
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Introduction


Till now we have seen how flow of execution can be defined in the Control Flow. There are trailing arrows after each task which defines the flow of execution. These arrows are called Precedence Constraints.

Precedence Constraint defines the execution flow not only by the state of the first task but also with the help of expressions. Combination of Expressions and Precedence Constraints make a Control Flow a powerful executable.

An important part of each application's Control Flow are the control structures, such as conditions and loop structures. SSIS, as an executable, has the ability to implement conditions with resort of Precedence Constraint. There are three types of containers in the Control Flow as shown in the following screenshot:

With Sequence Container, Control Flow Tasks get grouped together and will be considered as an executable object which has some properties. One of the most useful scenarios for sequence container is to use transactions which will be explored in...