mongoc_read_concern_t - Man Page
Read Concern abstraction
Synopsis
New in MongoDB 3.2.
The mongoc_read_concern_t allows clients to choose a level of isolation for their reads. The default, MONGOC_READ_CONCERN_LEVEL_LOCAL, is right for the great majority of applications.
You can specify a read concern on connection objects, database objects, or collection objects.
See readConcern <https://www.mongodb.com/docs/master/reference/readConcern/> on the MongoDB website for more information.
Read Concern is only sent to MongoDB when it has explicitly been set by mongoc_read_concern_set_level() <> to anything other than NULL.
Read Concern Levels
| Macro | Description | First MongoDB version |
| MONGOC_READ_CONCERN_LEVEL_LOCAL | Level "local", the default. | 3.2 |
| MONGOC_READ_CONCERN_LEVEL_MAJORITY | Level "majority". | 3.2 |
| MONGOC_READ_CONCERN_LEVEL_LINEARIZABLE | Level "linearizable". | 3.4 |
| MONGOC_READ_CONCERN_LEVEL_AVAILABLE | Level "available". | 3.6 |
| MONGOC_READ_CONCERN_LEVEL_SNAPSHOT | Level "snapshot". | 4.0 |
For the sake of compatibility with future versions of MongoDB, mongoc_read_concern_set_level() <> allows any string, not just this list of known read concern levels.
See Read Concern Levels <https://www.mongodb.com/docs/manual/reference/read-concern/#read-concern-levels> in the MongoDB manual for more information about the individual read concern levels.
Author
MongoDB, Inc
Copyright
2009-present, MongoDB, Inc.