C100DBA CRUD Operations Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  It forces the update to occur only on the primary node.

  Why it's wrong here

  Write concern defines the acknowledgment level, not the node selection. Updates are always directed to the primary node in a replica set. The 'majority' setting ensures the primary has successfully replicated the change to a sufficient number of secondary nodes before confirming success to the client application.

• ✓

  It ensures the data is replicated to most nodes before acknowledgment.

  Why this is correct

  Setting w: 'majority' ensures that the write operation is committed to a majority of the voting members in the replica set. This provides a high level of data durability, ensuring that if a failover occurs, the update will persist on the newly elected primary node.

• ✗

  It only updates documents that have a majority of fields set.

  Why it's wrong here

  Write concern is a configuration for acknowledgment, not a filter for the documents being updated. It has no impact on which documents match the query criteria. The update will apply to all documents where 'active' is false, regardless of how many fields are present in the documents.

• ✗

  It makes the update operation read-only.

  Why it's wrong here

  Write concern is strictly for write operations. It has nothing to do with read permissions or the type of operation being performed. The operation is a valid update, and the write concern simply specifies the durability guarantee level for the confirmation of that write to the client application.