SQL Server System Tables and Views - A Beginner's Reference

SQL Server provides a wealth of system tables and views that store essential information about the database's structure, metadata, and more. In this beginner's reference guide, we'll explore some of the most commonly used SQL Server system tables and views, their purposes, and provide sample code snippets to help you query and utilize them effectively.

Why Use System Tables and Views?

System tables and views are crucial for various tasks:

• Metadata Access: They store metadata about database objects, schemas, indexes, and constraints.
• Querying: You can use system tables and views to retrieve information about your database's structure and statistics.
• Diagnostic Purposes: System tables and views help in diagnosing issues and optimizing database performance.

Commonly Used System Views

Let's explore some commonly used system views and their purposes:

sys.objects

This view provides information about all objects in the database, including tables, views, stored procedures, and functions.

SELECT name, type_desc
FROM sys.objects;
    

sys.columns

Use this view to retrieve information about columns in tables or views.

SELECT name, system_type_name
FROM sys.columns
WHERE object_id = OBJECT_ID('YourTableName');
    

sys.indexes

For index-related information, including types and fragmentation:

SELECT name, type_desc, avg_fragmentation_in_percent
FROM sys.indexes
WHERE object_id = OBJECT_ID('YourTableName');
    

Querying System Views

Use simple SQL queries to retrieve information from system views. These views provide a wealth of metadata about your database and its objects.

What's Next?

As you become more familiar with SQL Server system tables and views, you can explore advanced topics like system procedures, system functions, and utilizing this knowledge for tasks like database maintenance and optimization.