DB2 SQL error: SQLCODE: -440, SQLSTATE: 42884, SQLERRMC: FORMAT_NAME;FUNCTION

I am getting this db2 error while running a sql query via java what i came to know is that format_name function is not present in db2 but when running this select query
select format_name('name1','name2','name3')marked_by from SYSIBM.SYSDUMMY1
i got a correct result.
not sure why this is showing up need some help in understanding this

thanks
Donraja_ht

the error means that:

No routine was found with the specified name and compatible arguments.

Please check whether you are providing the names of routines are correct along with arguments.

--Harsh