When not to index in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an index on the 'age' field in MongoDB.

MongoDB

db.users.createIndex({ age: [1] })

Drag options to blanks, or click blank then click option'

A-1

B1

Ctrue

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Using true or false instead of 1 or -1.

Omitting the value for the field.

In MongoDB, to create an ascending index on a field, you use 1 as the value.

2fill in blank

medium

Complete the code to drop an index named 'age_1' from the 'users' collection.

MongoDB

db.users.[1]('age_1')

Drag options to blanks, or click blank then click option'

Adrop

BdeleteIndex

CremoveIndex

DdropIndex

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'removeIndex' which does not exist.

Using 'drop' which drops the collection.

The correct method to remove an index by name in MongoDB is dropIndex.

3fill in blank

hard

Fix the error in the code to create a text index on the 'description' field.

MongoDB

db.products.createIndex({ description: [1] })

Drag options to blanks, or click blank then click option'

A'text'

Btext

C'Text'

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using text without quotes causes an error.

Using uppercase 'Text' is invalid.

The value for a text index must be the string 'text' (with quotes) in MongoDB.

4fill in blank

hard

Fill both blanks to create a compound index on 'category' ascending and 'price' descending.

MongoDB

db.items.createIndex({ category: [1], price: [2] })

Drag options to blanks, or click blank then click option'

A1

B-1

Ctrue

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Using true or false instead of 1 or -1.

Using the same value for both fields.

Ascending index uses 1 and descending uses -1 in MongoDB.

5fill in blank

hard

Fill all three blanks to create a partial index on 'status' equal to 'active' and sort by 'createdAt' descending.

MongoDB

db.records.createIndex({ status: [1], createdAt: [3] }, { partialFilterExpression: { status: [2] } })

Drag options to blanks, or click blank then click option'

A1

B'active'

C-1

Dstatus

Attempts:

3 left

💡 Hint

Common Mistakes

Using strings like 'active' for index directions.

Using 1 instead of -1 for descending.

Confusing partialFilterExpression syntax.

The index keys specify status: 1 (ascending) and createdAt: -1 (descending), the partialFilterExpression filters where status equals 'active'.