When you create a new database in SQL Server, you might assume that the system starts with an empty template and builds from scratch. In reality, every new database begins as a copy of model, one of the system databases. Understanding how model works, and how your changes affect downstream databases, is essential for anyone building, deploying, or maintaining SQL-based applications.
This article covers the 10 key concepts developers should understand to avoid surprises and to use the model database intentionally.
1. model Is the Template for Every New Database
Whenever you issue CREATE DATABASE, SQL Server copies the contents and settings of the model database.
That means: