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- cursor.readConcern()
cursor.readConcern()¶
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Definition¶
- cursor.readConcern(level)¶
New in version 3.2.
Specify a read concern for the db.collection.find() method.
The readConcern() method has the following form:
db.collection.find().readConcern(<level>)
The readConcern() method has the following parameter:
Parameter Type Description level string Optional. One of the following read concern modes: "local" or "majority" To use a read concern level of "majority", you must use the WiredTiger storage engine and start the mongod instances with the --enableMajorityReadConcern command line option (or the replication.enableMajorityReadConcern setting if using a configuration file).
Only replica sets using protocol version 1 support "majority" read concern. Replica sets running protocol version 0 do not support "majority" read concern.
To ensure that a single thread can read its own writes, use "majority" read concern and "majority" write concern against the primary of the replica set.
See also