SYNOPSIS

          void
          mongoc_write_concern_set_w (mongoc_write_concern_t *write_concern, int32_t w);

PARAMETERS

       • write_concern: A mongoc_write_concern_t <>.

       • w:          Use          MONGOC_WRITE_CONCERN_W_DEFAULT,         MONGOC_WRITE_CONCERN_W_UNACKNOWLEDGED,
         MONGOC_WRITE_CONCERN_W_MAJORITY, or a positive integer.

DESCRIPTION

       Sets the w value for the write concern. See  mongoc_write_concern_t  <>  for  more  information  on  this
       setting.

       Unacknowledged   writes   are  not  causally  consistent.  If  you  execute  a  write  operation  with  a
       mongoc_write_concern_t <> on which you have  called  mongoc_write_concern_set_w()  <>  with  a  value  of
       MONGOC_WRITE_CONCERN_W_UNACKNOWLEDGED,  the  write  does not participate in causal consistency, even when
       executed with a mongoc_client_session_t <>.

       Beginning in version 1.9.0, this function can now alter the write concern after it has been  used  in  an
       operation.  Previously,  using  the  struct  with an operation would mark it as "frozen" and calling this
       function would log a warning instead instead of altering the write concern.

Author

       MongoDB, Inc

Copyright

       2009-present, MongoDB, Inc.

2.2.1                                             Dec 11, 2025                     MONGOC_WRITE_CONCERN_SET_W(3)