#include <db.h>

int
DB_ENV->set_mp_max_openfd(DB_ENV *env, int maxopenfd);  

The DB_ENV->set_mp_max_openfd() method limits the number of file descriptors the library will open concurrently when flushing dirty pages from the cache.

The database environment's limit on open file descriptors to flush dirty pages may also be configured using the environment's DB_CONFIG file. The syntax of the entry in that file is a single line with the string "set_max_openfd", one or more whitespace characters, and the number of open file descriptors. Because the DB_CONFIG file is read when the database environment is opened, it will silently overrule configuration done before that time.

The DB_ENV->set_mp_max_openfd() method configures a database environment, not only operations performed using the specified DB_ENV handle.

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