That returns the current SQLID. If you want the host name of the server, see this link:
I think that gives the SERVER name of the local machine. CURRENT SQLID register would give the value of current sqlid right..? I Think if one has to find the SERVER name of the Remote database where the queries are executed then we need ot query the catalog SYIBM.SYSLOCATION, SYSIBM.SYSLUNAME. This catalog tables contains the DDF or CDB details.
Please feel free to correct me
IBM CERTIFIED DB2V8.1 APPLICATION DEVELOPER.