sysname and longsysname Datatypes

sysname and longsysname are user-defined datatypes that are distributed on the SAP ASE installation media and used in the system tables.

The definitions are:

You can declare a column, parameter, or variable to be of types sysname and longsysname. Alternately, you can also create a user-defined datatype with a base type of sysname and longsysname, and then define columns, parameters, and variables with the user-defined datatype.

All user-defined datatypes, including sysname and longsysname, are Transact-SQL extensions.