Bad data comes in many forms: duplicate rows, wrong data type, invalid values, and orphaned or missing foreign keys. Time is wasted cleansing, reviewing and correcting data, not to mention the potential hazards bad data can cause. This introductory presentation will explain the data types and constraints available in SQL Server, and how they can replace or augment business rules that would otherwise be written in application or procedure code. Performance benefits provided by constraints will be demonstrated. We will examine the various system views and procedures that describe constraints and how to use them to document your databases. You will be able to apply this knowledge to your database environments and see significant improvements in data quality, performance, and reliability.