SQL Server is made to help users manage and easily access important data about their applications and systems, which is exactly why it’s essential to make sure your instance is secure. Using a schema template without customizing it to the specific needs of your project, assuming all will be fine, simply won’t cut it in this case – you need to pay close attention to how you structure your application database schema.
The database schema documentation you create needs to define how your team intends to optimize data structures when uploading and querying information. In this way, it adds a layer of security to the system by spelling out exactly who can access which datasets on the server.
Having good schema design in place results in an SQL database that is less complex, has optimized query times, and, perhaps most importantly, is secure. On the flip side, bad schema design can lead to security vulnerabilities in the system.
In this article, I’ll explain why it’s important to have good schema design from the perspective of SQL Server security. We’ll also take a look at the different ways schema is used and its security implications.
Ensuring Database Integrity With Savvy Schemas
A database schema can be thought of as the skeleton structure that gives an overview of the logical view of the entire database. In other words, it represents what’s in the database by defining how the data is organized with procedures, views, functions and tables, while also defining how the relationships are associated. In addition to this, your schema formulates the various constraints that are applied to the data.
Put simply, the database schema helps users better understand relationships between the database tables. For example, is there a one-to-one relationship between Table A and Table B, or a one-to-many relationship?
It’s also worth noting that security permissions are best applied according to the specifications of database schemas. This makes your schema especially important for separating database objects based on user access rights. In this way, schemas act as an object protection tool when they’re combined with the correct user permissions.
Schemas organize database objects into logical groups, which is extremely useful when there are multiple teams working on the same database application. This also helps ensure that the integrity of the database tables stays intact.
Since the schema allows a logical grouping of database objects, it can also be used in scenarios where the name of the database object remains the same but it falls under a different logical group. In this way, schemas can make it easy to maintain the database.
Good Schema Design for Cybersecurity Protection
The main motivation behind having good schema design is that it helps with security management.
As we mentioned earlier, SQL schema makes it possible to organize various database objects into logical groups making it easier to manage complex databases. It can be used to define roles and access permissions to any part of the database.
For example, you can assign user permissions on a schema that will be applied to all of the database objects contained in that schema. This way, you can rest assured that authorized users have access to the correct data. It’s especially useful when there are multiple users or teams working on the same application, or when the application is deployed to a public cloud.
From a data security standpoint, it’s also important to implement schema-based access control. Ideally, databases should have some sort of built-in access control, and good schema design makes this possible.
Implementing general SQL configuration best practices for enhanced usability is crucial in the context of good schema design. Poor usability can lead people to make mistakes which can potentially lead to security vulnerabilities in the system. However, by following SQL schema rules and best practices, you can make it easier for your team to query data, without compromising your security posture.
Best Practices for Your SQL Schema
There are three main ways that schema is used: namespace, access control, and application interface.
Schemas are often used to divide the database up into logical groupings or workspaces. From a technical standpoint, the benefit of dividing databases up is to allow the same database object name to be used in different schemas without causing havoc.
That said, if the namespace schema model is mapped to logical application areas only, it can make access control difficult. In most cases, base tables are stored in namespace schemas even if the information contained within that table is required by different users with different user permissions and security requirements.
The problem with this is that it becomes too complex for access control and difficult to maintain. As a result, this can potentially lead to security vulnerabilities in the application.
Schemas can simplify defining and assigning user permissions to a great extent. This is because the permissions are inherited from the schema by the different database objects contained within the schema.
In this way, a database user can get permission to access all database objects within the schema once they’re assigned the correct database role. This not only makes it easy to manage database user permissions but also simplifies security management and access control for teams working on the same database.
Users of any database are assigned to the dbo schema by default, which exists in an empty database and is owned by the dbo user account. However, users can be explicitly assigned to a different schema.
One of the most impactful ways schemas can be used is by providing an application interface that essentially abstracts base tables behind different database objects such as procedures, views, and functions.
In this way, your SQL database can serve up only the data that’s necessary and required for the application. The key benefit here is that the application and database can be coupled loosely to avoid mismatches between different versions of each.
Application interface schema (or even multiple application interface schema) provide robust security for the database. Each application interface corresponds to a unique job role. The application then provides only what’s absolutely necessary for each job role through this application interface.
Application interfaces can use a combination of different database objects – such as procedures, views, and functions – that provide a subset of the database to the application that’s required by the job role. This sort of implementation is possible through ownership chaining.
Having a good database schema design is important for achieving optimal data management and data organization in a secure way. Schemas help admins to manage database objects and provide several security benefits, as well. By defining permissions on schemas rather than individual database objects, you’re able to better manage the overall database.
With well-planned schema documents in hand, you’ll be able to make it easier for your team to work on the same database application in a secure, efficient and organized manner.