SQL Server › Dynamic Data Masking

How would you apply dynamic data masking to an existing table with sensitive columns as part of a broader compliance initiative, such as meeting data privacy regulations?

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Answer

You would first identify all columns containing sensitive information such as national identification numbers, emails, or phone numbers, apply the most appropriate masking function to each one based on its data type and sensitivity, carefully audit who currently has UNMASK permission, and document the masking strategy as part of your organization's overall compliance evidence.

ALTER TABLE Customers
ALTER COLUMN NationalId ADD MASKED WITH (FUNCTION = 'default()');

ALTER TABLE Customers
ALTER COLUMN Email ADD MASKED WITH (FUNCTION = 'email()');

Real-world example A healthcare company applies dynamic data masking across several sensitive columns in its patient database as part of a broader compliance effort, carefully documenting which roles have UNMASK permission for an upcoming audit.

Common follow-ups: What documentation is typically required to demonstrate compliance when using dynamic data masking?;How often should masking configurations be reviewed as regulations or team roles change?

SQL Server Security & Permissions;Row Level Security