cursor.addOption()¶

Definition¶

cursor.addOption(flag)¶

Adds OP_QUERY wire protocol flags, such as the tailable flag, to change the behavior of queries.

The cursor.addOption() method has the following parameter:

Parameter	Type	Description
`flag`	flag	`OP_QUERY` wire protocol flag. See MongoDB wire protocol for more information on MongoDB Wire Protocols and the OP_QUERY flags. For the `mongo` shell, you can use cursor flags. For the driver-specific list, see your driver documentation.

Flags¶

The mongo shell provides several additional cursor flags to modify the behavior of the cursor.

DBQuery.Option.tailable¶

DBQuery.Option.slaveOk¶

DBQuery.Option.oplogReplay¶

DBQuery.Option.noTimeout¶

DBQuery.Option.awaitData¶

DBQuery.Option.exhaust¶

DBQuery.Option.partial¶

For a description of the flags, see MongoDB wire protocol.

Example¶

The following example adds the DBQuery.Option.tailable flag and the DBQuery.Option.awaitData flag to ensure that the query returns a tailable cursor. The sequence creates a cursor that will wait for few seconds after returning the full result set so that it can capture and return additional data added during the query:

var t = db.myCappedCollection;
var cursor = t.find().addOption(DBQuery.Option.tailable).
                      addOption(DBQuery.Option.awaitData)

Warning

Adding incorrect wire protocol flags can cause problems and/or extra server load.

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