#include <db.h> int DB_MPOOLFILE->sync(DB_MPOOLFILE *mpf);
         The DB_MPOOLFILE->sync() method writes all modified pages associated with
         the DB_MPOOLFILE  back to the source file.  If any of the
         modified pages are pinned (that is, currently in use),
         DB_MPOOLFILE->sync() will ignore them.
    
         The DB_MPOOLFILE->sync() 
            
                  method returns a non-zero error value on failure and 0 on success.