Find Interview Questions for Codingmart Technologies

Right Answer:
Replication in MongoDB is the process of copying data from one database server (primary) to one or more other servers (secondaries). It ensures high availability by maintaining multiple copies of data across different servers. If the primary server fails, one of the secondary servers can automatically be elected as the new primary, allowing the database to continue operating without downtime.

Right Answer:
MongoDB is a NoSQL database that stores data in flexible, JSON-like documents, allowing for dynamic schemas, while MySQL is a relational database that uses structured tables with fixed schemas and SQL for querying.

Right Answer:
To query documents in MongoDB using filters, you can use the `find()` method with a filter object. For example:

```javascript
db.collectionName.find({ field: value });
```

This will return all documents in `collectionName` where the specified `field` matches the given `value`. You can also use operators like `$gt`, `$lt`, `$in`, etc., to create more complex queries.

Right Answer:
BSON (Binary JSON) is a binary-encoded serialization format used by MongoDB to store documents and data. It extends JSON by adding additional data types, such as Date and Binary, which allows for more efficient storage and retrieval of data. BSON is used internally by MongoDB to represent documents in collections.

Right Answer:
MongoDB Atlas is a cloud-based database service provided by MongoDB that simplifies database management by automating tasks such as deployment, scaling, backups, and monitoring. It allows users to easily create, manage, and scale MongoDB databases without the need for extensive infrastructure management.

Right Answer:
The types of Firebase Database Rules are:

1. **Read Rules** - Control who can read data.
2. **Write Rules** - Control who can write data.
3. **Validation Rules** - Ensure data meets certain criteria before being written.

Right Answer:
The Firebase Realtime Database has the following limits:

1. Maximum database size: 1 GB.
2. Maximum number of simultaneous connections: 100,000.
3. Maximum data size for a single write: 256 MB.
4. Maximum depth of data: 32 levels.
5. Maximum number of nodes: 32,000,000.
6. Maximum size of a single node: 10 MB.

These limits may vary based on usage and pricing plans.

Right Answer:
The method used to sign in the user in Firebase Email/Password authentication is `signInWithEmailAndPassword(email, password)`.

Right Answer:
SHA-1 is used in Firebase for generating a unique identifier for your app's signing certificate, which is necessary for authenticating your app with Firebase services, particularly for features like Firebase Authentication and Google Sign-In.

Right Answer:
Firebase Analytics is used to collect and analyze user behavior data in mobile and web applications, helping developers understand how users interact with their app and make data-driven decisions to improve user experience and engagement.

Right Answer:

Security Groups are virtual firewalls in AWS that control inbound and outbound traffic to AWS resources, such as EC2 instances. They allow you to specify rules based on IP addresses, protocols, and ports to manage access.

Right Answer:

To secure data in transit in AWS, use SSL/TLS for encryption during transmission and implement VPNs or AWS Direct Connect for secure connections. To secure data at rest, use AWS services like S3 Server-Side Encryption, EBS encryption, and RDS encryption, along with IAM policies to control access.

Right Answer:

A Public Subnet is a subnet that has a route to the internet through an Internet Gateway, allowing resources within it to be accessed from the internet. A Private Subnet, on the other hand, does not have a direct route to the internet, meaning resources in it cannot be accessed directly from the internet.

Right Answer:

AWS Lambda is a serverless computing service that allows you to run code in response to events without provisioning or managing servers. It automatically scales and charges only for the compute time consumed.

Right Answer:

AWS CLI (Amazon Web Services Command Line Interface) is a tool that allows users to interact with AWS services using command-line commands instead of the web-based console.