#include <db.h> int DBcursor->set_priority(DBC *DbCursor, DB_CACHE_PRIORITY priority);
Set the cache priority for pages referenced by the DBcursor handle.
         The priority of a page biases the replacement algorithm to be more or
         less likely to discard a page when space is needed in the buffer pool.
         The bias is temporary, and pages will eventually be discarded if they
         are not referenced again.  The DBcursor->set_priority() method is
         only advisory, and does not guarantee pages will be treated in a
         specific way.
    
         The DBcursor->set_priority() method may be called at any time during
         the life of the application.
    
         The DBcursor->set_priority() 
            
                  method returns a non-zero error value on failure and 0 on success.
            
            
        
    
The priority parameter must be set to one of the following values:
The lowest priority: pages are the most likely to be discarded.
The next lowest priority.
The default priority.
The next highest priority.
The highest priority: pages are the least likely to be discarded.