#include <db.h> int DB_ENV->get_mp_max_openfd(DB_ENV *env, int *maxopenfdp);
Returns the maximum number of file descriptors the library will open concurrently when flushing dirty pages from the cache. This value is set by the DB_ENV->set_mp_max_openfd() method.
         The DB_ENV->get_mp_max_openfd() method may be called at any time
         during the life of the application.
    
         The DB_ENV->get_mp_max_openfd() 
            
                  method returns a non-zero error value on failure and 0 on success.