#include <db.h>

int
DB_MPOOLFILE->set_pgcookie(DB_MPOOLFILE *mpf, DBT *pgcookie);  

The DB_MPOOLFILE->set_pgcookie() method specifies a byte string that is provided to the functions registered to do input or output processing of the file's pages as they are read from or written to, the backing filesystem store. (See the DB_ENV->memp_register() documentation for more information.)

The DB_MPOOLFILE->set_pgcookie() method configures a file in the cache, not only operations performed using the specified DB_MPOOLFILE handle.

The DB_MPOOLFILE->set_pgcookie() method may not be called after the DB_MPOOLFILE->open() method is called. If the file is already open in the cache when DB_MPOOLFILE->open() is called, the information specified to DB_MPOOLFILE->set_pgcookie() will replace the existing information.

The DB_MPOOLFILE->set_pgcookie() method returns a non-zero error value on failure and 0 on success.