#include <db_cxx.h> void DbEnv::set_errpfx(const char *errpfx);
Set the prefix string that appears before error messages issued by Berkeley DB.
         The Db::set_errpfx() 
         and DbEnv::set_errpfx() methods do not copy the memory to which the
         errpfx parameter refers; rather, they
         maintain a reference to it.  Although this allows applications to
         modify the error message prefix at any time (without repeatedly
         calling the interfaces), it means the memory must be maintained until
         the handle is closed.
    
         The DbEnv::set_errpfx() method configures operations performed using
         the specified DbEnv 
         handle, not all operations performed on the underlying database
         environment.
    
         The DbEnv::set_errpfx() method may be called at any time during the
         life of the application.