This topic describes the encryption functions and compression functions. Some functions are not supported by PolarDB-X 1.0.

Supported encryption functions and compression functions

The following table describes the encryption functions and compression functions that are supported by PolarDB-X 1.0.

Function Description
AES_ENCRYPT() Encrypt using AES
MD5() Calculate MD5 checksum
UNCOMPRESS() Uncompress a string compressed
UNCOMPRESSED_LENGTH() Return the length of a string before compression

Unsupported encryption functions and compression functions

The following table describes the encryption functions and compression functions that are not supported by PolarDB-X 1.0. These functions are supported by databases that run on the MySQL 5.7 engine.

Function Description
AES_DECRYPT() Decrypt using AES
AES_ENCRYPT() Encrypt using AES
ASYMMETRIC_DECRYPT() Decrypt ciphertext using private or public key
ASYMMETRIC_DERIVE() Derive symmetric key from asymmetric keys
ASYMMETRIC_ENCRYPT() Encrypt cleartext using private or public key
ASYMMETRIC_SIGN() Generate signature from digest
ASYMMETRIC_VERIFY() Verify that signature matches digest
CREATE_ASYMMETRIC_PRIV_KEY() Create private key
CREATE_ASYMMETRIC_PUB_KEY() Create public key
CREATE_DH_PARAMETERS() Generate shared DH secret
CREATE_DIGEST() Generate digest from string
DECODE() (deprecated 5.7.2) Decodes a string encrypted using ENCODE()
DES_DECRYPT() (deprecated 5.7.6) Decrypt a string
DES_ENCRYPT() (deprecated 5.7.6) Encrypt a string
ENCODE() (deprecated 5.7.2) Encode a string
ENCRYPT() (deprecated 5.7.6) Encrypt a string
OLD_PASSWORD() Return the value of the pre-4.1 implementation of PASSWORD
PASSWORD() (deprecated 5.7.6) Calculate and return a password string
RANDOM_BYTES() Return a random byte vector
SHA1(), SHA() Calculate an SHA-1 160-bit checksum
SHA2() Calculate an SHA-2 checksum
VALIDATE_PASSWORD_STRENGTH() Determine strength of password