NO.50 The difference between $push and $addToSet is:

第 51 号 You perform the following query on the sayings collection, which has the index
{ quote : “text” }:
Assuming the documents below are in the collection, which ones will the following query return? Check all that apply.
db.sayings.find( { $text : { $search : “fact find” } } )

第 52 号 Consider a collection posts which has fields: Jd, post_text, post_author, post_timestamp, post_tags etc. Which of the following query retrieves ONLY the key named post_text from the first document retrieved?

第 53 号 When should we consider representing a one-to-many relationship in an embedded collection instead of separate collection?

第 54 号 In a sharded cluster, from which node does one stop the balancer process before initiating backup?

第 55 号 What tool do you use to see if you have a problem in the consumption of disk I / 0?

NO.56 Which of the following is true of the mechanics of replication in MongoDB? Check all that apply.

NO.57 Which mongodb tool is used to report details on number of database operations in MongoDB?

NO.58 What read preference should your application use if you want to read from the primary under normal circumstances but allow reads from secondaries when a primary is unavailable?

第 59 号 Consider that the posts collection contains an array called ratings which contains ratings given to the post by various users in the following format:

Which of the following query will return all the documents where the ratings array contains elements that in some combination satisfy the query conditions?

NO.60 Which of the following command inside aggregate command is used in MongoDB aggregation to filter the documents to pass only the documents that match the specified condition(s) to the next pipeline stage.

第 61 号 Consider the following example document:
{
“_id”: Objectld(“5360c0a0a655a60674680bbe”),
“user”
“login”: “irOn”
“description”: “Made of steel”
“date”: ISODate(“2014-04-30T09:16:45.836Z”),
}
>
and index creation command:
db.users.createlndex( { “user.login”: 1, “user.date”: -1 }, “mylndex” ) When performing the following query:
db.users.find( { “user.login”: /Air.*/ },
{ “user”:1, “_id”:0 > ).sort( { “user.date”:1 > )
which of the following statements correctly describe how MongoDB will handle the query? Check all that apply.

第 62 号 The oplog (operations log) is a special capped collection that keeps a rolling record of all operations that modify the data stored in your databases. All the replica set members contain a copy of the oplog in the following collection:

NO.63 Mongodb does provide high availability via which option?

NO.64 Which of the following aggregate commands in MongoDB uses a pipeline approach with the goals of improving the aggregation performance?

第 65 号 The following aggregation option is used to specify the specific fields that needs to be passed to the next stage of the aggregation pipeline:

NO.66 The________operator can be used to identify an element in the array to be updated without explicitly specifying the position of the element.

NO.67 Which of the following is supported by MongoDB?

NO.68 In a replica set, a_________number of members ensures that the replica set is always able to select a primary.