db_env_set_func_fsync |
#include <db.h>int db_env_set_func_fsync(int (*func_fsync)(int fd));
Replace Berkeley DB calls to the IEEE/ANSI Std 1003.1 (POSIX) fsync function with func_fsync, which must conform to the standard interface.
The db_env_set_func_fsync interface affects the entire application, not a single database or database environment.
While the db_env_set_func_fsync interface may be used to configure Berkeley DB at any time during the life of the application, it should normally be called before making any calls to the db_env_create or db_create functions.
The db_env_set_func_fsync function returns a non-zero error value on failure and 0 on success.