Server System Variables Scope Global, Session Dynamic Yes SET_VAR  Hint Applies No Type String Default Value aes-128-ecb This variable controls the block encryption mode for block-based algorithms such as AES. It affects encryption for  AES_ENCRYPT()  and  AES_DECRYPT() . block_encryption_mode  takes a value in  aes- keylen - mode  format, where  keylen  is the key length in bits and  mode  is the encryption mode. The value is not case-sensitive. Permitted  keylen values are 128, 192, and 256. Permitted  mode  values are  ECB ,  CBC ,  CFB1 ,  CFB8 ,  CFB128 , and  OFB . For example, this statement causes the AES encryption functions to use a key length of 256 bits and the CBC mode: SET block_encryption_mode = ’aes-256-cbc’; An error occurs for attempts to set  block_encryption_mode  to a value containing an unsupported key length or a mode that the SSL library does not support. • bulk_insert_buffer_size Command-Line Format --bulk-insert-buffer-size=# System Variable bulk_insert_buffer_size Scope Global, Session Dynamic Yes SET_VAR  Hint Applies Yes Type Integer Default Value 8388608 Minimum Value 0 Maximum Value (64-bit platforms) 18446744073709551615 Maximum Value (32-bit platforms) 4294967295 As of MySQL 8.0.14, setting the session value of this system variable is a restricted operation. The session user must have privileges sufficient to set restricted session variables. See Section 5.1.9.1, “System Variable Privileges” . • caching_sha2_password_digest_rounds Command-Line Format --caching-sha2-password-digest- rounds=# Introduced 8.0.24 System Variable caching_sha2_password_digest_rounds 775 MyISAM  uses a special tree-like cache to make bulk inserts faster for  INSERT ... SELECT , INSERT ... VALUES (...), (...), ... , and  LOAD DATA  when adding data to nonempty tables. This variable limits the size of the cache tree in bytes per thread. Setting it to 0 disables this optimization. The default value is 8MB.