MariaDB starting with 10.10.0
The RANDOM_BYTES function generates a binary string of random bytes. It was added in MariaDB 10.10.0.
Given a length from 1 to 1024, generates a binary string of length consisting of random bytes generated by the SSL library's random number generator.
See the RAND_bytes() function documentation of your SSL library for information on the random number generator. In the case of OpenSSL, a cryptographically secure pseudo random generator (CSPRNG) is used.
Statements containing the RANDOM_BYTES function are unsafe for replication.
An error occurs if length is outside the range 1 to 1024.