最新のC100DEV問題集で試験を準備する

MongoDB C100DEV 試験概要:

MongoDB C100DEV 試験シラバストピック:

MongoDB Certified Developer Associate 認定 C100DEV 試験問題：

1. Select all true statements regarding to schema validation in MongoDB.

A) We need to use db.createCollection() with the validator option to specify validation rules for a new collection.
B) MongoDB doesn't provide the capability to perform schema validation during updates and insertions.
C) Validation rules are on a per-collection basis.

2. Suppose you insert the following documents into companies collection: db.companies.insertMany([ {"_id": 1, "name": "Facebook"}, {"_id": 1, "name": "Twitter"}, {"_id": 2, "name": "Tesla"}, {"_id": 3, "name": "Amazon"} ], {"ordered": false}) Select all true statements about this operation. (select 3)

A) One document will be inserted into the collection.
B) Three documents will be inserted into the collection.
C) This insert is unordered.
D) Two documents will be inserted into the collection.
E) MongoDB will insert each document with a unique _id value into the collection.

3. Which of the following statements are true regarding MongoDB views?

A) MongoDB views are created on demand and reflect the data in the source collection.
B) Write operations to views will raise an error.
C) Views are write only.
D) Views are read only.
E) MongoDB views themselves don't contain data.

4. Suppose you have a companies collection in your database. Only the following documents are stored in this collection: { _id: ObjectId("52cdef7c4bab8bd675297da4"), name: 'Powerset', category_code: 'search', founded_year: 2006 }, { _id: ObjectId("52cdef7c4bab8bd675297da5"), name: 'Technorati', category_code: 'advertising', founded_year: 2002 }, { _id: ObjectId("52cdef7c4bab8bd675297da7"), name: 'AddThis', category_code: 'advertising', founded_year: 2004 }, { _id: ObjectId("52cdef7c4bab8bd675297da8"), name: 'OpenX', category_code: 'advertising', founded_year: 2008 }, { _id: ObjectId("52cdef7c4bab8bd675297daa"), name: 'Sparter', category_code: 'games_video', founded_year: 2007 }, { _id: ObjectId("52cdef7c4bab8bd675297dac"), name: 'Veoh', category_code: 'games_video', founded_year: 2004 }, { _id: ObjectId("52cdef7c4bab8bd675297dae"), name: 'Thoof', category_code: 'web', founded_year: 2006 } How many documents will be returned in response to the following aggregation pipeline? [{ $group: { _id: '$category_code', number_of_companies: { $sum: 1 } }}, { $sort: { number_of_companies: -1 }}, { $limit: 3 }]

A) 2
B) 0
C) 3
D) 4

5. What is the best practice in using the $match operator?

A) It doesn't matter when we apply $match stage.
B) The earlier in the pipeline, the better. Not only because we will be using expression filters which reduce the number of documents to be processed, but also because we can use indexes.
C) The later in the pipeline, the better.

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