#include <db_cxx.h> int DbMpoolFile::set_priority(DB_CACHE_PRIORITY priority);
Set the cache priority for pages referenced by the DbMpoolFile 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 cache.
         The bias is temporary, and pages will eventually be discarded if they
         are not referenced again.  The DbMpoolFile::set_priority() method is
         only advisory, and does not guarantee pages will be treated in a
         specific way.
    
         To set the priority for the pages belonging to a particular database,
         call the DbMpoolFile::set_priority() method using the 
         DbMpoolFile  handle
         returned by the Db::get_mpf()  method.
    
         The DbMpoolFile::set_priority() method configures a file in the
         cache, not only operations performed using the specified 
         DbMpoolFile  handle.
    
         The DbMpoolFile::set_priority() method may be called at any time
         during the life of the application.
    
         The DbMpoolFile::set_priority() 
            
            
                method either returns a non-zero error value or throws an
                exception that encapsulates a non-zero error value on
                failure, and returns 0 on success.
            
        
    
The priority parameter must be set to one of the following values:
                  DB_PRIORITY_VERY_LOW
            
The lowest priority: pages are the most likely to be discarded.
                  DB_PRIORITY_LOW
            
The next lowest priority.
                  DB_PRIORITY_DEFAULT
            
The default priority.
                  DB_PRIORITY_HIGH
            
The next highest priority.
                  DB_PRIORITY_VERY_HIGH
            
The highest priority: pages are the least likely to be discarded.