1MONGOC_WRITE_CONCERN_T(3)          libmongoc         MONGOC_WRITE_CONCERN_T(3)
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5Write Concern abstraction
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SYNOPSIS

8       mongoc_write_concern_t  tells  the driver what level of acknowledgement
9       to await from the server. The default,  MONGOC_WRITE_CONCERN_W_DEFAULT,
10       is right for the great majority of applications.
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12       You  can  specify  a  write concern on connection objects, database ob‐
13       jects, collection objects, or per-operation. Data-modifying  operations
14       typically  use  the  write  concern  of the object they operate on, and
15       check the server response for a write concern error  or  write  concern
16       timeout.  For  example, mongoc_collection_drop_index() uses the collec‐
17       tion's write concern, and a write concern error or timeout in  the  re‐
18       sponse is considered a failure.
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20       Exceptions to this principle are the generic command functions:
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22       • mongoc_client_command()
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24       • mongoc_client_command_simple()
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26       • mongoc_database_command()
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28       • mongoc_database_command_simple()
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30       • mongoc_collection_command()
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32       • mongoc_collection_command_simple()
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34       These generic command functions do not automatically apply a write con‐
35       cern, and they do not check the server response for a write concern er‐
36       ror or write concern timeout.
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38       See Write Concern on the MongoDB website for more information.
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WRITE CONCERN LEVELS

41       Set the write concern level with mongoc_write_concern_set_w().
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43              ┌───────────────────────────┬────────────────────────────┐
44              │MONGOC_WRITE_CONCERN_W_DE‐ │ By default,  writes  block │
45              │FAULT (1)                  │ awaiting   acknowledgement │
46              │                           │ from MongoDB. Acknowledged │
47              │                           │ write    concern    allows │
48              │                           │ clients to catch  network, │
49              │                           │ duplicate  key,  and other │
50              │                           │ errors.                    │
51              ├───────────────────────────┼────────────────────────────┤
52              │MONGOC_WRITE_CONCERN_W_UN‐ │ With  this  write concern, │
53              │ACKNOWLEDGED (0)           │ MongoDB does not  acknowl‐ │
54              │                           │ edge  the receipt of write │
55              │                           │ operation.  Unacknowledged │
56              │                           │ is  similar  to errors ig‐ │
57              │                           │ nored; however, mongoc at‐ │
58              │                           │ tempts to receive and han‐ │
59              │                           │ dle  network  errors  when │
60              │                           │ possible.                  │
61              └───────────────────────────┴────────────────────────────┘
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67              │MONGOC_WRITE_CONCERN_W_MA‐ │ Block until  a  write  has │
68              │JORITY (majority)          │ been  propagated  to a ma‐ │
69              │                           │ jority of the nodes in the │
70              │                           │ 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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941.25.1                           Nov 08, 2023        MONGOC_WRITE_CONCERN_T(3)
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