NAME

       mongoc_session_opts_set_causal_consistency - mongoc_session_opts_set_causal_consistency()

SYNOPSIS

          void
          mongoc_session_opts_set_causal_consistency (mongoc_session_opt_t *opts,
                                                      bool causal_consistency);

       Configure  causal  consistency  in a session. If true (the default), each operation in the
       session will be causally ordered after the previous read or write operation. Set to  false
       to disable causal consistency. See the MongoDB Manual Entry for Causal Consistency.

       Causal  consistency  and  snapshot reads are mutually exclusive. Attempting to set both to
       true will result in an error. See mongoc_session_opts_set_snapshot().

       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 0, the write does not participate in causal consistency.

PARAMETERS

       • opts: A mongoc_session_opt_t.

       • causal_consistency: True or false.

EXAMPLE

          mongoc_client_t *client;
          mongoc_session_opt_t *session_opts;
          mongoc_client_session_t *client_session;
          mongoc_collection_t *collection;
          bson_t insert_opts = BSON_INITIALIZER;
          bson_t *doc;
          bson_error_t error;
          bool r;

          client = mongoc_client_new ("mongodb://example/?appname=session-opts-example");
          mongoc_client_set_error_api (client, 2);

          session_opts = mongoc_session_opts_new ();
          mongoc_session_opts_set_causal_consistency (session_opts, false);
          client_session = mongoc_client_start_session (client, session_opts, &error);
          mongoc_session_opts_destroy (session_opts);

          if (!client_session) {
             fprintf (stderr, "Failed to start session: %s\n", error.message);
             abort ();
          }

          collection = mongoc_client_get_collection (client, "test", "collection");
          doc = BCON_NEW ("_id", BCON_INT32 (1));
          r = mongoc_client_session_append (client_session, &insert_opts, NULL);
          if (!r) {
             fprintf (stderr, "mongoc_client_session_append failed: %s\n", error.message);
             abort ();
          }

          r = mongoc_collection_insert_one (
             collection, doc, &insert_opts, NULL /* reply */, &error);

          if (!r) {
             fprintf (stderr, "Insert failed: %s\n", error.message);
             abort ();
          }

AUTHOR

       MongoDB, Inc

COPYRIGHT

       2017-present, MongoDB, Inc

1.22.1                                     Aug 02, 2MONGOC_SESSION_OPTS_SET_CAUSAL_CONSISTENCY(3)