"you seems to be confused between db link name and db alias name."

db alias names default to the db name if no other name is mentioned for that during the db creation. so in my case, pdsource is both the db name and db alias name.
dblink name is the name of the db link that i create between "pdsource" and "uii.world" - which i have kept as 'uii.world" keeping the global_names parameter in the pfile = true.
am i wrong somewhere??????