mysql>  SET @stmt = ’SELECT * FROM mytable WHERE cola = 10 AND colb = 20’; mysql>  SELECT STATEMENT_DIGEST(@stmt); +------------------------------------------------------------------+ | STATEMENT_DIGEST(@stmt) | +------------------------------------------------------------------+ | 3bb95eeade896657c4526e74ff2a2862039d0a0fe8a9e7155b5fe492cbd78387 | +------------------------------------------------------------------+ mysql>  SELECT STATEMENT_DIGEST_TEXT(@stmt); +----------------------------------------------------------+ | STATEMENT_DIGEST_TEXT(@stmt) | +----------------------------------------------------------+ | SELECT * FROM ‘mytable‘ WHERE ‘cola‘ = ? AND ‘colb‘ = ? | +----------------------------------------------------------+ mysql>  SELECT UNCOMPRESS(COMPRESS(’any string’)); -> ’any string’ mysql>  SELECT UNCOMPRESS(’any string’); -> NULL mysql>  SELECT UNCOMPRESSED_LENGTH(COMPRESS(REPEAT(’a’,30))); -> 30 2276 • VALIDATE_PASSWORD_STRENGTH( str ) • UNCOMPRESSED_LENGTH( compressed_string ) The password is subjected to increasingly strict tests and the return value reflects which tests were satisfied, as shown in the following table. In addition, if the Password assessment by  VALIDATE_PASSWORD_STRENGTH()  is done by the  validate_password component. If that component is not installed, the function always returns 0. For information about installing  validate_password , see Section 6.4.3, “The Password Validation Component” . To examine or configure the parameters that affect password testing, check or set the system variables implemented by  validate_password . See Section 6.4.3.2, “Password Validation Options and Variables” . Given an argument representing a plaintext password, this function returns an integer to indicate how strong the password is. The return value ranges from 0 (weak) to 100 (strong). Returns the length that the compressed string had before being compressed. Uncompresses a string compressed by the  COMPRESS()  function. If the argument is not a compressed value, the result is  NULL . This function requires MySQL to have been compiled with a compression library such as  zlib . Otherwise, the return value is always  NULL . Given an SQL statement as a string, returns the normalized statement digest as a string in the connection character set, or  NULL  if the argument is  NULL . For additional discussion and examples, see the description of the related  STATEMENT_DIGEST()  function. • STATEMENT_DIGEST_TEXT( statement ) • UNCOMPRESS( string_to_uncompress ) The  max_digest_length  system variable determines the maximum number of bytes available to these functions for computing normalized statement digests. Both functions use the MySQL parser to parse the statement. If parsing fails, an error occurs. The error message includes the parse error only if the statement is provided as a literal string. function returns the normalized statement digest. For information about statement digesting, see Section 27.10, “Performance Schema Statement Digests and Sampling” . Encryption and Compression Functions