#include <db.h> int DB->get_q_extentsize(DB *db, u_int32_t *extentsizep);
         The DB->get_q_extentsize() method returns the number of pages in an
         extent. This value is used only for Queue databases and is set using the
         DB->set_q_extentsize()
         method.
    
         The DB->get_q_extentsize() method may be
         called only after the database has been opened.
    
         The DB->get_q_extentsize() 
            
                  method returns a non-zero error value on failure and 0 on success.