#include <db_cxx.h> int DbMpoolFile::set_flags(int ftype);
         The DbMpoolFile::set_ftype() method specifies a file type for the
         purposes of input or output processing of the file's pages as they are
         read from or written to, the backing filesystem store.
    
         The DbMpoolFile::set_ftype() method configures a file in the 
         cache, not only operations performed using the specified 
         DbMpoolFile  handle.
    
         The DbMpoolFile::set_ftype() method may not be called after the
         DbMpoolFile::open() 
         method is called. If the file is already open in the cache when
         DbMpoolFile::open()  is
         called, the information specified to DbMpoolFile::set_ftype() will
         replace the existing information.
    
         The DbMpoolFile::set_ftype() 
            
            
                method either returns a non-zero error value or throws an
                exception that encapsulates a non-zero error value on
                failure, and returns 0 on success.
            
        
    
The ftype parameter sets the file's type for the purposes of input and output processing. The ftype must be the same as a ftype parameter previously specified to the DbEnv::memp_register() method.