To refer to the current or next value of a sequence in the schema of another user, you must have been granted either
SELECT
object privilege on the sequence or SELECT
ANY
SEQUENCE
system privilege, and you must qualify the sequence with the schema containing it:schema.sequence.CURRVAL schema.sequence.NEXTVALTo refer to the value of a sequence on a remote database, you must qualify the sequence with a complete or partial name of a database link:
schema.sequence.CURRVAL@dblink schema.sequence.NEXTVAL@dblink
Reference: http://docs.oracle.com/cd/B19306_01/server.102/b14200/pseudocolumns002.htm