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


A package is executable and acts like an application. One of the basic requirements in every application is to work with variables. SSIS has the following two types of variables:

  • System variables: System variables are used to fetch system information at a specific place in a package

  • User variables: User variables can be used to read and write through their scope in the package

Expressions as we have talked about them till now are a way to provide calculations and write logic in basic semi-functional expressions. The use of expressions is not limited to Derived Column or Conditional Split transforms, but they are widely used throughout the package. Expressions provide a method of setting property values dynamically, so using expressions is a way to dynamism in SSIS.

There are different types of dynamism. Control Flow Tasks can work with dynamic properties, for example attachments of a Send Mail Task can be set dynamically based on a variable value or an expression. There is a common...