#include <db_cxx.h>

int DbMpoolFile::set_clear_len(u_int32_t len); 

The DbMpoolFile::set_clear_len() method sets the number of initial bytes in a page that should be set to nul when the page is created as a result of the DB_MPOOL_CREATE or DB_MPOOL_NEW flags specified to DbMpoolFile::get() . If no clear length is specified, the entire page is cleared when it is created.

The DbMpoolFile::set_clear_len() method configures a file in the cache, not only operations performed using the specified DbMpoolFile handle.

The DbMpoolFile::set_clear_len() method may not be called after the DbMpoolFile::open() method is called. If the file is already open in the cache when DbMpoolFile::open() is called, the information specified to DbMpoolFile::set_clear_len() must be consistent with the existing file or an error will be returned.

The DbMpoolFile::set_clear_len() 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.