Row-Level Security

Row-Level Security (RLS) restricts access to individual rows in a SQL Server table based on the characteristics of the user executing the query. Introduced in SQL Server 2016, RLS enables fine-grained access control without modifying application logic.

RLS uses predicate functions and security policies to filter rows transparently. For example, a sales manager may only see orders from their region, even though the table contains all orders.

Benefits:

• Enforced at the server level (non-bypassable).
• Simplifies security in multi-user environments.
• Compatible with both views and stored procedures.

RLS is particularly useful in SaaS and compliance-heavy applications where tenant data segregation is critical.