1MONGOC_WRITE_CONCERN_T(3)          libmongoc         MONGOC_WRITE_CONCERN_T(3)
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NAME

6       mongoc_write_concern_t - mongoc_write_concern_t
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8       Write Concern abstraction
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SYNOPSIS

11       mongoc_write_concern_t  tells  the driver what level of acknowledgement
12       to await from the server. The default,  MONGOC_WRITE_CONCERN_W_DEFAULT,
13       is right for the great majority of applications.
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15       You  can  specify  a  write  concern  on  connection  objects, database
16       objects, collection objects, or  per-operation.  Data-modifying  opera‐
17       tions  typically  use  the write concern of the object they operate on,
18       and check the server response for a write concern error or  write  con‐
19       cern  timeout.  For example, mongoc_collection_drop_index uses the col‐
20       lection's write concern, and a write concern error or  timeout  in  the
21       response is considered a failure.
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23       Exceptions to this principle are the generic command functions:
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25       · mongoc_client_command
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27       · mongoc_client_command_simple
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29       · mongoc_database_command
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31       · mongoc_database_command_simple
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33       · mongoc_collection_command
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35       · mongoc_collection_command_simple
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37       These generic command functions do not automatically apply a write con‐
38       cern, and they do not check the server response  for  a  write  concern
39       error or write concern timeout.
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41       See Write Concern on the MongoDB website for more information.
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WRITE CONCERN LEVELS

44       Set the write concern level with mongoc_write_concern_set_w.
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46              ┌───────────────────────────┬────────────────────────────┐
47              │MONGOC_WRITE_CON‐          │ By default,  writes  block │
48              │CERN_W_DEFAULT (1)         │ awaiting   acknowledgement │
49              │                           │ from MongoDB. Acknowledged │
50              │                           │ write    concern    allows │
51              │                           │ clients to catch  network, │
52              │                           │ duplicate  key,  and other │
53              │                           │ errors.                    │
54              ├───────────────────────────┼────────────────────────────┤
55              │MONGOC_WRITE_CON‐          │ With  this  write concern, │
56              │CERN_W_UNACKNOWLEDGED (0)  │ MongoDB does not  acknowl‐ │
57              │                           │ edge  the receipt of write │
58              │                           │ operation.  Unacknowledged │
59              │                           │ is   similar   to   errors │
60              │                           │ ignored;  however,  mongoc │
61              │                           │ attempts  to  receive  and │
62              │                           │ handle network errors when │
63              │                           │ possible.                  │
64              └───────────────────────────┴────────────────────────────┘
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67              │MONGOC_WRITE_CON‐          │ Block until  a  write  has │
68              │CERN_W_MAJORITY (majority) │ been   propagated   to   a │
69              │                           │ majority of the  nodes  in │
70              │                           │ the replica set.           │
71              ├───────────────────────────┼────────────────────────────┤
72              │n                          │ Block  until  a  write has │
73              │                           │ been  propagated   to   at │
74              │                           │ least   n   nodes  in  the │
75              │                           │ replica set.               │
76              └───────────────────────────┴────────────────────────────┘
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DEPRECATIONS

79       The write concern MONGOC_WRITE_CONCERN_W_ERRORS_IGNORED (value -1) is a
80       deprecated synonym for MONGOC_WRITE_CONCERN_W_UNACKNOWLEDGED (value 0),
81       and will be removed in the next major release.
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83       mongoc_write_concern_set_fsync is deprecated.
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AUTHOR

86       MongoDB, Inc
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89       2017-present, MongoDB, Inc
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941.16.2                           Feb 25, 2020        MONGOC_WRITE_CONCERN_T(3)
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