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. For more information, see sys.dm_database_encryption_keys (Transact-SQL).

Requires CONTROL permission on the database.

A. Dropping a Database Encryption Key

ALTER DATABASE AdventureWorks
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 AdventureWorks
GO
DROP DATABASE ENCRYPTION KEY;
GO

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