DROP DATABASE ENCRYPTION KEY (Transact-SQL)

Artikkeli
09/03/2024

Applies to: SQL Server Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW)

Drops a database encryption key that is used in transparent database encryption. For more information about transparent database encryption, see Transparent Data Encryption (TDE).

Important

The backup of the certificate that was protecting the database encryption key should be retained even if the encryption is no longer enabled on a database. Even though the database is not encrypted anymore, parts of the transaction log may still remain protected, and the certificate may be needed for some operations until the full backup of the database is performed.

Transact-SQL syntax conventions

Syntax

DROP DATABASE ENCRYPTION KEY

Note

This syntax is not supported by serverless SQL pool in Azure Synapse Analytics.

Remarks

If the database is encrypted, you must first remove encryption from the database by using the ALTER DATABASE statement. Wait for decryption to complete before removing the database encryption key. For more information about the ALTER DATABASE statement, see ALTER DATABASE SET Options (Transact-SQL). To view the state of the database, use the sys.dm_database_encryption_keys dynamic management view.

Permissions

Requires CONTROL permission on the database.

Examples

The following example removes the database encryption and drops the database encryption key.

ALTER DATABASE AdventureWorks2022  
SET ENCRYPTION OFF;  
GO  
/* Wait for decryption operation to complete, look for a   
value of  1 in the query below. */  
SELECT encryption_state  
FROM sys.dm_database_encryption_keys;  
GO  
USE AdventureWorks2022;  
GO  
DROP DATABASE ENCRYPTION KEY;  
GO

Examples: Azure Synapse Analytics and Analytics Platform System (PDW)

The following example removes the TDE encryption and then drops the database encryption key.

ALTER DATABASE AdventureWorksPDW2012  
    SET ENCRYPTION OFF;  
GO  
/* Wait for decryption operation to complete, look for a   
value of  1 in the query below. */  
WITH dek_encryption_state AS   
(  
    SELECT ISNULL(db_map.database_id, dek.database_id) AS database_id, encryption_state  
    FROM sys.dm_pdw_nodes_database_encryption_keys AS dek  
        INNER JOIN sys.pdw_nodes_pdw_physical_databases AS node_db_map  
           ON dek.database_id = node_db_map.database_id AND dek.pdw_node_id = node_db_map.pdw_node_id  
        LEFT JOIN sys.pdw_database_mappings AS db_map  
            ON node_db_map .physical_name = db_map.physical_name  
        INNER JOIN sys.dm_pdw_nodes AS nodes  
            ON nodes.pdw_node_id = dek.pdw_node_id  
    WHERE dek.encryptor_thumbprint <> 0x  
)  
SELECT TOP 1 encryption_state  
       FROM  dek_encryption_state  
       WHERE dek_encryption_state.database_id = DB_ID('AdventureWorksPDW2012 ')  
       ORDER BY (CASE encryption_state WHEN 3 THEN -1 ELSE encryption_state END) DESC;   
GO  
USE AdventureWorksPDW2012;  
GO  
DROP DATABASE ENCRYPTION KEY;  
GO

Jaa

DROP DATABASE ENCRYPTION KEY (Transact-SQL)

Syntax

Remarks

Permissions

Examples

Examples: Azure Synapse Analytics and Analytics Platform System (PDW)

See Also

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