Explanation:For the case of client-generated messages, it will be returned in the responseTo field of the OP_REPLY message. 9. Which of the following operator is not very selective ?
A. $nine
B. $nin
C. $ain
D. None of the mentioned
Answer:A
Explanation:For the case of client-generated messages, it will be returned in the responseTo field of the OP_REPLY message. 9. Which of the following operator is not very selective ?
A. $nine B. $nin C. $ain D. None of the mentioned
Explanation:The inequality operators $nin and $ne are not very selective since they often match a large portion of the index. 10. An index cannot cover a query on a _______ collection when run against a mongos if the index does not contain the shard key.