ALTER TABLESPACE

Purpose

You can use this statement to modify the encryption method of a tablespace.

Required privileges

To execute the ALTER TABLESPACE statement, you must have the CREATE TABLESPACE privilege. For more information about privileges in OceanBase Database, see Privilege types in MySQL mode.

Syntax

• Modify an encrypted tablespace.

  ALTER TABLESPACE tablespace_name ENCRYPTION [=] 'tablespace_encryption_option';
  
  tablespace_encryption_option:
      N
      | Y
      | AES-256
      | AES-256-GCM
      | AES-128
      | AES-128-GCM
      | AES-192
      | AES-192-GCM
      | SM4-CBC
      | SM4-GCM
  

• Modify a tablespace.

  ALTER TABLESPACE tablespace_name
    {ADD | DROP} DATAFILE 'file_name'
    [INITIAL_SIZE [=] size]
    [WAIT]
    ENGINE [=] engine_name
  

  Notice

  Only the keyword syntax is supported. The functionality does not actually take effect. You cannot use this keyword in combination with ENCRYPTION. Otherwise, a syntax error will be returned.

Parameters

tablespace_encryption_option

• N: specifies not to enable encryption for the tablespace.
• Y: specifies to enable encryption for the tablespace. By default, the AES-256 encryption algorithm is used.
• AES-256: uses a 256-bit key for encryption and decryption.
• AES-256-GCM: uses Galois/Counter Mode (GCM) with a 256-bit key.
• AES-128: uses a 128-bit key for encryption and decryption.
• AES-128-GCM: uses GCM with a 128-bit key.
• AES-192: uses a 192-bit key for encryption and decryption.
• AES-192-GCM: uses GCM with a 192-bit key.
• SM4-CBC: uses the SM4 algorithm in Cipher Block Chaining (CBC) mode, where before each block of data is encrypted, it undergoes an XOR operation with the encrypted output of the previous block.
• SM4-GCM: uses the SM4 algorithm in GCM mode, which provides both encryption and authentication functionalities.

Examples

Enable the unencrypted tablespace named tablespace001 to use the SM4-GCM encryption algorithm.

ALTER TABLESPACE tablespace001 ENCRYPTION = 'SM4-GCM';