Explanation:executionStats contains statistics that describe the completed query execution for the winning plan. 2. Point out the correct statement :
A. In MongoDB 3.0, cursor.explain() returns the indexOnly field to indicate whether the index covered a query
B. When an index covers a query, MongoDB can both match the query conditions and return the results using only the index keys
C. For read-heavy applications, deploy sharding and add one or more shards to a sharded cluster to distribute load among mongod instances
D. All of the mentioned
Answer:A
Explanation:executionStats contains statistics that describe the completed query execution for the winning plan. 2. Point out the correct statement :
A. In MongoDB 3.0, cursor.explain() returns the indexOnly field to indicate whether the index covered a query B. When an index covers a query, MongoDB can both match the query conditions and return the results using only the index keys C. For read-heavy applications, deploy sharding and add one or more shards to a sharded cluster to distribute load among mongod instances D. All of the mentioned
Explanation:MongoDB does not need to examine documents from the collection to return the results. 3. _________ corresponds to the millis field returned by cursor.explain() in earlier versions of MongoDB.