Book Image

Data Modeling with Snowflake

By : Serge Gershkovich
5 (2)
Book Image

Data Modeling with Snowflake

5 (2)
By: Serge Gershkovich

Overview of this book

The Snowflake Data Cloud is one of the fastest-growing platforms for data warehousing and application workloads. Snowflake's scalable, cloud-native architecture and expansive set of features and objects enables you to deliver data solutions quicker than ever before. Yet, we must ensure that these solutions are developed using recommended design patterns and accompanied by documentation that’s easily accessible to everyone in the organization. This book will help you get familiar with simple and practical data modeling frameworks that accelerate agile design and evolve with the project from concept to code. These universal principles have helped guide database design for decades, and this book pairs them with unique Snowflake-native objects and examples like never before – giving you a two-for-one crash course in theory as well as direct application. By the end of this Snowflake book, you’ll have learned how to leverage Snowflake’s innovative features, such as time travel, zero-copy cloning, and change-data-capture, to create cost-effective, efficient designs through time-tested modeling principles that are easily digestible when coupled with real-world examples.
Table of Contents (24 chapters)
1
Part 1: Core Concepts in Data Modeling and Snowflake Architecture
8
Part 2: Applied Modeling from Idea to Deployment
14
Part 3: Solving Real-World Problems with Transformational Modeling

Constraints and enforcement

The remainder of this chapter deals with table constraints, so it is necessary to understand what they are and to mention several important details regarding their use in Snowflake. In the ANSI-SQL standard, constraints define integrity and consistency rules for data stored in tables. Snowflake supports four constraint types:

  • PRIMARY KEY
  • UNIQUE
  • FOREIGN KEY
  • NOT NULL

Since the function of each of these constraints is covered later in this chapter, this section will be limited to their enforcement.

Enforcement, on the part of the database, means actively monitoring the integrity rules of a given constraint when DML operations are performed on a table. By enforcing a constraint, a database ensures that an error is raised when the constraint is violated, and the offending DML operation is not allowed to complete.

For example, a NOT NULL constraint on a column indicates that this column cannot contain NULL values. By enforcing...