Data Correction with Data Quality Services - SQL Server Integration Services Design Patterns - page 140

CHAPTER 5
Data Correction with Data Qual-
ity Services
Data Quality Services (DQS) was first introduced in SQL Server 2012. It provides data
correction and data deduplication functionality—key components for most Extract,
Transform, and Load (ETL) processes. This chapter describes how DQS integrates with
SSIS and provides patterns that enable you to achieve reliable, low-effort data cleansing
within your ETL packages.
Note The Data Quality Services product requires some manual steps post-installation
to create the DQS databases and set default permissions. See the “Install Data Quality
Services” page in topics Online for more information: ht-
tp://msdn.microsoft.com/en-us/library/gg492277.aspx .
Overview of Data Quality Services
The data cleansing and matching operations you perform with DQS revolve around the
use of a knowledge base. A knowledge base (or KB) is made up of one or more do-
mains. An example domain for doing address cleansing would be City , State , or
Country . Each of these fields would be a separate domain. Two or more related do-
mains can be grouped together to form a composite domain (or CD). Composite do-
mains allow you to validate multiple fields as a single unit. For example, a Company