MongoDB Certification Exams

Introduction

MongoDB offers certification exams for developers and database administrators to validate their skills and knowledge. These certifications can help professionals advance their careers and demonstrate their expertise in MongoDB.

Available Certifications

MongoDB Certified Developer Associate

This certification is for developers who build applications using MongoDB. It covers topics such as MongoDB architecture, CRUD operations, indexing, aggregation, and data modeling.

MongoDB Certified DBA Associate

This certification is for database administrators who manage MongoDB deployments. It includes topics such as installation, configuration, backup and recovery, monitoring, and performance tuning.

Exam Details

The certification exams are conducted online and consist of multiple-choice questions. Each exam is designed to test the candidate's practical knowledge and problem-solving abilities.

Preparation Tips

• Review the official MongoDB documentation and study guides.
• Complete relevant MongoDB training courses and practice exams.
• Gain hands-on experience by working on real-world MongoDB projects.

Example Question: Aggregation

Here is an example of a question that might appear on the MongoDB Certified Developer Associate exam:

// Given the following documents in a collection named 'sales':
{ "_id": 1, "item": "apple", "quantity": 10, "price": 2.5 }
{ "_id": 2, "item": "banana", "quantity": 5, "price": 1.0 }
{ "_id": 3, "item": "orange", "quantity": 8, "price": 3.0 }

// Which of the following aggregation pipelines calculates the total sales for each item?
a) 
db.sales.aggregate([
    { $group: { _id: "$item", totalSales: { $sum: { $multiply: ["$quantity", "$price"] } } } }
])

b) 
db.sales.aggregate([
    { $group: { _id: "$item", totalSales: { $sum: "$quantity" } } }
])

c) 
db.sales.aggregate([
    { $group: { _id: "$item", totalSales: { $sum: "$price" } } }
])

The correct answer is a). This pipeline groups the documents by item and calculates the total sales by multiplying the quantity by the price for each item.

Conclusion

MongoDB certification exams are a valuable way to validate your skills and knowledge. By preparing thoroughly and gaining hands-on experience, you can successfully earn MongoDB certifications and advance your career.