Syntax
------ 
UUID_SHORT()
 
Description
----------- 
Returns a "short" universal identifier as a 64-bit
unsigned integer (rather
than a string-form 128-bit identifier as returned by the
UUID() function).
 
The value of UUID_SHORT() is guaranteed to be unique if the
following conditions hold:
The server_id of the current host is unique among your set
of master and
 slave servers
server_id is between 0 and 255
You don't set back your system time for your server between
mysqld restarts
You do not invoke UUID_SHORT() on average more than 16
 million times per second between mysqld restarts
 
The UUID_SHORT() return value is constructed this way:
 
 (server_id & 255) 

URL: https://mariadb.com/kb/en/uuid_short/