#include <db.h> int DB->get_pagesize(DB *db, u_int32_t *pagesizep);
        The DB->get_pagesize() method returns the database's current page size, as
        set by the DB->set_pagesize()
        method. Note that if DB->set_pagesize() was not called by your
        application, then the default pagesize is selected based on the underlying filesystem I/O block size.
        If you call DB->get_pagesize() before you have opened the
        database, the value returned by this method is therefore the underlying filesystem I/O block size.
    
         The DB->get_pagesize() method may be called only after the database has been opened.
    
         The DB->get_pagesize() 
            
                  method returns a non-zero error value on failure and 0 on success.