Spanner supports the following MySQL encryption and compressionfunctions. You need to implement the MySQL functions in yourSpanner database before you can use them. For more information oninstalling the functions, seeInstall MySQL functions.

Function list

mysql.SHA2

mysql.SHA2(bytes_expression,hash_length)

Description

Calculates an SHA-2 checksum for the inputBYTES.

This function supports the following arguments:

• bytes_expression: TheBYTES value for which to calculate the checksum.
• hash_length: The chosen bit length of the hash. Supported values are 256and 512.

Return data type

STRING

Differences from MySQL

The MySQL version ofSHA2() also supports SHA-224 and SHA-384 hash lengths,which this function does not. Additionally, this function returns the checksum as ahexadecimalSTRING, while the MySQL version returns binary data.

Limitations

This function only supports hash lengths of 256 and 512 bits. The output isalways a hexadecimal string, not binary data. If you provide an unsupportedhash_length, the function returns an error.

Example

The following example calculates the SHA-256 checksum for aBYTES value:

SELECTmysql.SHA2(B'GoogleCloud',256)assha256_checksum;/*+------------------------------------------------------------------+| sha256_checksum                                                  |+------------------------------------------------------------------+| 2002A3F1F350598F5FAF799AD9C9936908230796712E24682016E5257A4D2000 |+------------------------------------------------------------------+*/