R4RIN – MCQs, Mock Tests | MongoDB MongoDB Mcq Question Set 13

Point out the correct statement.

1. If an appropriate index exists for a query, MongoDB cannot use the index to limit the number of documents it must inspect
2. Indexes support the efficient execution of queries in MongoDB
3. The index stores the location of a specific field or set of fields, ordered by the value of the field
4. None of the mentioned

✅ Correct Answer: 2

MongoDB supports the creation of user-defined ascending/descending indexes on a ______ field of a document.

1. Single
2. Non Unique
3. Compound
4. none of the mentioned

✅ Correct Answer: 1

The ______ index is unique and prevents clients from inserting two documents with the same value for the _id field.

1. _id
2. $default
3. _def
4. None of the mentioned

✅ Correct Answer: 1

Point out the wrong statement.

1. MongoDB can return sorted results by using the ordering in the index
2. MongoDB defines indexes at the collection level and supports indexes on any field or sub-field of the documents in a MongoDB collection
3. Fundamentally, indexes in MongoDB is different to indexes in other database systems
4. None of the mentioned

✅ Correct Answer: 3

MongoDB also supports user-defined indexes on multiple fields called ___

1. compound
2. composite
3. candidate
4. None of the mentioned

✅ Correct Answer: 1

MongoDB uses ______ indexes to index the content stored in arrays.

1. singlekey
2. multikey
3. compkey
4. None of the mentioned

✅ Correct Answer: 2

______ indexes use spherical geometry to return results.

1. 3dsphere
2. 2dsphere
3. 1dsphere
4. none of the mentioned

✅ Correct Answer: 2

MongoDB provides a ________ index type that supports searching for string content in a collection.

1. string
2. text
3. char
4. None of the mentioned

✅ Correct Answer: 2

_____ indexes uses planar geometry when returning results.

1. 2d
2. 1d
3. 3d
4. All of the mentioned

✅ Correct Answer: 1

To support ________ based sharding, MongoDB provides a hashed index type.

1. primary
2. root
3. hash
4. All of the Mentioned

✅ Correct Answer: 3

Point out the correct statement.

1. Whether the use of a compound index or the use of an index intersection is more efficient depends on the particular query and the system
2. Certain restrictions apply to indexes, such as the length of the index keys or the number of indexes per collection
3. For queries that specify compound query conditions, if one index can fulfill a part of a query condition, and another index can fulfill another part of the query condition, then MongoDB can use the i
4. None of the mentioned

✅ Correct Answer: 4

_______ index type, which indexes the hash of the value of a field.

1. Hashed
2. Unique
3. Multikey
4. None of the mentioned

✅ Correct Answer: 1

The _________ property for an index causes MongoDB to reject duplicate values for the indexed field.

1. Hashed
2. Unique
3. Multikey
4. None of the mentioned

✅ Correct Answer: 3

Point out the wrong statement.

1. TTL index is ideal for certain types of information like machine generated event data, logs, and session information that only need to persist in a database for a finite amount of time
2. You cannot combine the sparse index option with the unique index option
3. TTL indexes are special indexes that MongoDB can use to automatically remove documents from a collection after a certain amount of time
4. none of the mentioned

✅ Correct Answer: 2

The ______ property of an index ensures that the index only contain entries for documents that have the indexed field.

1. Hashed
2. Unique
3. Sparse
4. None of the mentioned

✅ Correct Answer: 3

MongoDB can use the _________ of indexes to fulfill queries.

1. union
2. intersection
3. projection
4. None of the mentioned

✅ Correct Answer: 2

Which of the following method is to verify whether MongoDB used index intersection?

1. explain()
2. analyze()
3. intersect()
4. None of the mentioned

✅ Correct Answer: 1

An index prefix is a subset of a ______ index, consisting of one or more keys starting from the beginning of the index.

1. Hashed
2. Unique
3. Sparse
4. Compound

✅ Correct Answer: 4

Index __________ does not eliminate the need for creating compound indexes.

1. union
2. addition
3. intersection
4. All of the Mentioned

✅ Correct Answer: 3

Before version _______ capped collections did not have an _id field.

1. 2.1
2. 2.4
3. 3.0
4. 2.2

✅ Correct Answer: 4

Point out the wrong statement.

1. You can create indexes on fields within embedded documents
2. Indexes on embedded fields are similar to indexes on embedded documents
3. Indexes on embedded fields allow you to use a “dot notation,” to introspect into embedded documents
4. None of the mentioned

✅ Correct Answer: 3

For a _____ multikey index, each indexed document can have at most one indexed field whose value is an array.

1. Hashed
2. Unique
3. Multikey
4. compound

✅ Correct Answer: 4

Which of the following indexes cannot be multikey?

1. Hashed
2. Unique
3. Multikey
4. compound

✅ Correct Answer: 1

Point out the wrong statement.

1. You may not create compound indexes that have hashed index fields
2. The order of the fields in a compound index is very important
3. You will receive a warning if you attempt to create a compound index that includes a hashed index
4. none of the mentioned

✅ Correct Answer: 3

To calculate geometry over an Earth-like sphere, store your location data on a spherical surface and use _____ index.

1. 2dsphere
2. 2d
3. geoHaystack
4. All of the Mentioned

✅ Correct Answer: 1

_____ indexes can be constructed over arrays that hold both scalar values (e.g. strings, numbers) and nested documents.

1. Hashed
2. Unique
3. Multikey
4. compound

✅ Correct Answer: 3

The coordinate reference system for GeoJSON uses the _____ datum.

1. WGS88
2. WGS84
3. JGS88
4. none of the mentioned

✅ Correct Answer: 2

Which of the following is used to calculate distances on a Euclidean plane?

1. 2dsph
2. 2d
3. geoHaystack
4. All of the Mentioned

✅ Correct Answer: 2

Queries on ________ objects always calculate on a sphere.

1. GeoBSON
2. GeoJSON
3. geoJSONB
4. All of the Mentioned

✅ Correct Answer: 2

Which of the following GeoJSON object is not supported in MongoDB?

1. Point
2. LineString
3. MultiPoint
4. None of the mentioned

✅ Correct Answer: 4

Point out the wrong statement.

1. MongoDB can query for locations contained entirely within a specified polygon
2. MongoDB require an index for inclusion queries; however, such indexes will improve query performance
3. Indexes on embedded fields allow you to use a “dot notation,” to introspect into embedded documents
4. none of the mentioned

✅ Correct Answer: 2

MongoDB supports spherical surface calculations on legacy coordinate pairs using a _______ index.

1. 2dsphere
2. 2d
3. geoHaystack
4. All of the Mentioned

✅ Correct Answer: 1

Inclusion queries use the _________ operator in MongoDB.

1. $geokey
2. $geoin
3. $geoWithin
4. All of the mentioned

✅ Correct Answer: 3

Point out the correct statement.

1. For $geoSphere queries that specify GeoJSON geometries with areas greater than a single hemisphere, the use of the default CRS results in queries for the complementary geometries
2. When determining inclusion, MongoDB considers the border of a shape to be part of the shape, subject to the precision of floating point numbers
3. The custom MongoDB CRS uses a anti-clockwise winding order
4. None of the mentioned

✅ Correct Answer: 2

The $geoWithin operator uses the _______ operator to specify the GeoJSON object.

1. $sphere
2. $geoin
3. $geometry
4. All of the Mentioned

✅ Correct Answer: 3

If the specified polygon is _______ than a single hemisphere, the behavior of $geoWithin with the MongoDB CRS is the same as with the default CRS.

1. smaller
2. bigger
3. equal
4. All of the Mentioned

✅ Correct Answer: 1

To query with a single-ringed GeoJSON polygon whose area is greater than a single hemisphere, the $geometry expression must specify the custom MongoDB ________

1. CRS
2. CDS
3. CLS
4. None of the mentioned

✅ Correct Answer: 1

$geoWithin replaces _______ in MongoDB 2.4.

1. $withing
2. $gwithin
3. $within
4. All of the Mentioned

✅ Correct Answer: 3

When used with the _____ operator, $geoWithin returns documents based on grid coordinates and does not query for GeoJSON shapes.

1. $box
2. $circle
3. $shape
4. All of the mentioned

✅ Correct Answer: 1

_____ indexes expire documents after the specified number of seconds has passed since the indexed field value.

1. Hashed
2. Unique
3. Multikey
4. TTL

✅ Correct Answer: 4

Point out the correct statement.

1. If you build a TTL index in the foreground, MongoDB does not remove expired documents as soon as the index finishes building
2. The TTL index does guarantee that expired data will be deleted immediately upon expiration
3. Duration of the removal operation depends on the workload of your mongod instance
4. None of the mentioned

✅ Correct Answer: 3

The background task that removes expired documents runs every ________ seconds.

1. 15
2. 45
3. 60
4. 120

✅ Correct Answer: 3

Point out the wrong statement.

1. The unique constraint applies to separate documents in the collection
2. Unique index prevents separate documents from having the same value for the indexed key
3. Index does prevent a document from having multiple elements or embedded documents in an indexed array from having the same value
4. none of the mentioned

✅ Correct Answer: 3

On replica sets, the TTL background thread only deletes documents on _____

1. primary
2. secondary
3. upadte
4. none of the mentioned

✅ Correct Answer: 1

You can combine the ________ constraint with the sparse index to filter these null values from the unique index and avoid the error.

1. Hashed
2. Unique
3. Sparse
4. Compound

✅ Correct Answer: 3

You may not specify a unique constraint on a ______ index.

1. Hashed
2. Unique
3. Sparse
4. compound

✅ Correct Answer: 1

Which of the following indexes are always sparse?

1. 2dsphere
2. 2d
3. geoHaystack
4. All of the mentioned

✅ Correct Answer: 4

To modify an existing index, you cannot just re-issue the _________ method with the updated specification of the index.

1. dropIndex()
2. modIndex()
3. createIndex()
4. None of the mentioned

✅ Correct Answer: 3

Point out the wrong statement.

1. To modify an existing index, you need to drop and recreate the index
2. Your client library may have a different or additional interface for this operation
3. To see the status of an indexing process, you can use the db.statusOp() method in the mongo shell
4. None of the mentioned

✅ Correct Answer: 3

If you need to rebuild indexes for a collection you can use the _________ method to rebuild all indexes on a collection in a single operation.

1. db.collection.Index()
2. db.collection.reIndex()
3. db.collection.rebuildIndex()
4. None of the mentioned

✅ Correct Answer: 1

To terminate an ongoing index build, use the __________ method in the mongo shell.

1. db.currentOp()
2. db.killOp()
3. db.removeOp()
4. All of the mentioned

✅ Correct Answer: 2

Point out the correct statement.

1. After 4.0, you cannot terminate both background index builds and foreground index builds
2. Before MongoDB 2.1, you could only terminate background index builds
3. After 2.4, you can terminate both background index builds and foreground index builds
4. None of the mentioned

✅ Correct Answer: 3

In the mongo shell, you can use the ______ method to return a list of the indexes on a collection.

1. getallIndexes()
2. getretIndexes()
3. getIndexes()
4. none of the mentioned

✅ Correct Answer: 3

____ views partial execution statistics collected during plan selection.

1. curs.explain()
2. cursor.explain()
3. cursr.explain()
4. All of the Mentioned

✅ Correct Answer: 2

The __________ operator constrains the results of a geospatial $near or $nearSphere query to the specified distance.

1. $center
2. $maxDistance
3. $minDistance
4. All of the mentioned

✅ Correct Answer: 2

To force MongoDB to use a particular index for a db.collection.________ operation, specify the index with the hint() method.

1. query()
2. find()
3. index()
4. All of the mentioned

✅ Correct Answer: 2

Specify the ______ operator to the hint() method to prevent MongoDB from using any index.

1. $unique
2. $natural
3. $spatial
4. All of the Mentioned

✅ Correct Answer: 2

______ selects geometries that intersect with a GeoJSON geometry.

1. $near
2. $nearsphere
3. $geoIntersect
4. None of the mentioned

✅ Correct Answer: 3

Point out the wrong statement.

1. If $near or $nearSphere query specifies the center point as a GeoJSON point, specify the distance as a non-negative number in meters
2. If $nearSphere query specifies the center point as legacy coordinate pair, specify the distance as a non-negative number in radians
3. $near can only use the 2dsphere index if the query specifies the center point as a GeoJSON point
4. None of the mentioned

✅ Correct Answer: 4

______ returns geospatial objects in proximity to a point.

1. $near
2. $nearsphere
3. $geoIntersect
4. None of the mentioned

✅ Correct Answer: 1