SQL Data Discovery and Classification
Applies to: SQL Server (all supported versions)
Data Discovery & Classification adds capabilities for discovering, classifying, labeling & reporting the sensitive data in your databasesc. This can be done via T-SQL or using SQL Server Management Studio (SSMS) . Discovering and classifying your most sensitive data (business, financial, healthcare, etc.) can play a pivotal role in your organizational information protection stature. It can serve as infrastructure for:
- Helping meet data privacy standards.
- Monitoring access to databases/columns containing highly sensitive data.
Data Discovery & Classification is supported for SQL Server 2012 and later, and can be used with SSMS 17.5 or later. For Azure SQL Database, see Azure SQL Database Data Discovery & Classification.
Data Discovery & Classification forms a new information-protection paradigm for SQL Database, SQL Managed Instance, and Azure Synapse, aimed at protecting the data and not just the database. Currently it supports the following capabilities:
- Discovery & recommendations - The classification engine scans your database and identifies columns containing potentially sensitive data. It then provides you an easy way to review and apply the appropriate classification recommendations, as well as to manually classify columns.
- Labeling - Sensitivity classification labels can be persistently tagged on columns.
- Visibility - The database classification state can be viewed in a detailed report that can be printed/exported to be used for compliance & auditing purposes, as well as other needs.
Discovering, classifying & labeling sensitive columns
The following section describes the steps for discovering, classifying, and labeling columns containing sensitive data in your database, as well as viewing the current classification state of your database and exporting reports.
The classification includes two metadata attributes:
- Labels - The main classification attributes, used to define the sensitivity level of the data stored in the column.
- Information Types - Provide additional granularity into the type of data stored in the column.
To classify your SQL Server database:
In SQL Server Management Studio (SSMS) connect to the SQL Server.
In the SSMS Object Explorer, right click on the database that you would like to classify and choose Tasks > Data Discovery and Classification > Classify Data....
The classification engine scans your database for columns containing potentially sensitive data and provides a list of recommended column classifications:
To view the list of recommended column classifications, click on the recommendations notification box at the top or the recommendations panel at the bottom of the window:
Review the list of recommendations:
To accept a recommendation for a specific column, check the checkbox in the left column of the relevant row. You can also mark all recommendations as accepted by checking the checkbox in the recommendations table header.
You can also change the recommended Information Type and Sensitivity Label using the drop down boxes.
To apply the selected recommendations, click on the blue Accept selected recommendations button.
You can also manually classify columns as an alternative, or in addition, to the recommendation-based classification:
Click on Add classification in the top menu of the window.
In the context window that opens, select the schema > table > column that you want to classify, and the information type and sensitivity label. Then click on the blue Add classification button at the bottom of the context window.
To complete your classification and persistently label (tag) the database columns with the new classification metadata, click on Save in the top menu of the window.
To generate a report with a full summary of the database classification state, click on View Report in the top menu of the window. (You can also generate a report using SSMS. Right click on the database where you would like to generate the report, and choose Tasks > Data Discovery and Classification > Generate Report...)
Manage information protection policy with SSMS
You can manage the information protection policy using SSMS 18.4 or later:
In SQL Server Management Studio (SSMS) connect to the SQL Server.
In the SSMS Object Explorer, right click on one of your databases and choose Tasks > Data Discovery and Classification.
The following menu options allow you to manage the information protection policy:
Set Information Protection Policy File: uses the information protection policy as defined in the selected JSON file.
Export Information Protection Policy: exports the information protection policy to a JSON file.
Reset Information Protection Policy: resets the information protection policy to the default information protection policy.
Information protection policy file is not stored in the SQL Server. SSMS uses a default information protection policy. If an information protection policy customized fails, SSMS cannot use the default policy. Data classification fails. To resolve, click Reset Information Protection Policy to use the default policy and re-enable data classification.
Accessing the classification metadata
SQL Server 2019 introduces
sys.sensitivity_classifications system catalog view. This view returns information types and sensitivity labels.
On SQL Server 2019 instances, query
sys.sensitivity_classifications to review all classified columns with their corresponding classifications. For example:
SELECT schema_name(O.schema_id) AS schema_name, O.NAME AS table_name, C.NAME AS column_name, information_type, label, rank, rank_desc FROM sys.sensitivity_classifications sc JOIN sys.objects O ON sc.major_id = O.object_id JOIN sys.columns C ON sc.major_id = C.object_id AND sc.minor_id = C.column_id
Prior to SQL Server 2019, the classification metadata for information types and sensitivity labels is in the following Extended Properties:
For instances of SQL Server 2017 and prior, the following example returns all classified columns with their corresponding classifications:
SELECT schema_name(O.schema_id) AS schema_name, O.NAME AS table_name, C.NAME AS column_name, information_type, sensitivity_label FROM ( SELECT IT.major_id, IT.minor_id, IT.information_type, L.sensitivity_label FROM ( SELECT major_id, minor_id, value AS information_type FROM sys.extended_properties WHERE NAME = 'sys_information_type_name' ) IT FULL OUTER JOIN ( SELECT major_id, minor_id, value AS sensitivity_label FROM sys.extended_properties WHERE NAME = 'sys_sensitivity_label_name' ) L ON IT.major_id = L.major_id AND IT.minor_id = L.minor_id ) EP JOIN sys.objects O ON EP.major_id = O.object_id JOIN sys.columns C ON EP.major_id = C.object_id AND EP.minor_id = C.column_id
On SQL Server 2019 instances, viewing classification requires VIEW ANY SENSITIVITY CLASSIFICATION permission. For more information, see Metadata Visibility Configuration.
Prior to SQL Server 2019, the metadata can be accessed using the Extended Properties catalog view
Managing classification requires ALTER ANY SENSITIVITY CLASSIFICATION permission. The ALTER ANY SENSITIVITY CLASSIFICATION is implied by the database permission ALTER, or by the server permission CONTROL SERVER.
You can use T-SQL to add/remove column classifications, as well as retrieve all classifications for the entire database.