MERGE [hint] INTO [schema .] table [t_alias] USING [schema .] 
{ table | view | subquery } [t_alias] ON ( condition ) 
WHEN MATCHED THEN merge_update_clause 
WHEN NOT MATCHED THEN merge_insert_clause;

For information on the symbols and conventions of Backus-Naur Form (BNF) syntax, see Appendix A.