________ is a security practice that involves encoding information so that only authorized parties can access it.
- Encryption
- Hashing
- Salting
- Obfuscation
Encryption is a security practice that involves encoding information in a way that only authorized parties with the decryption key can access it. This is commonly used to protect sensitive data during transmission and storage.
In a system following eventual consistency, what implications does it have on Read operations after a Write operation?
- Strong consistency
- Read operations may return stale data
- Write operations are blocked until consistency is achieved
- Write operations are delayed
In a system with eventual consistency, Read operations may return stale or outdated data for a period of time after a Write operation. This is because eventual consistency prioritizes availability and performance over strict consistency. Strong consistency (Option 1) ensures that all reads return the most recent write but may lead to higher latency. Options 3 and 4 are not characteristic of eventual consistency.
How can you define optional route parameters in Express.js?
- Enclose parameters in square brackets [param]
- Use the optional keyword before the parameter
- Use the ? symbol after the parameter
- Wrap parameters in parentheses (param)
In Express.js, you can define optional route parameters by using the ? symbol after the parameter name, like /route/:param?. This makes the parameter optional, allowing it to match both routes with and without that parameter. The other options do not represent the correct way to define optional route parameters in Express.js.
You are tasked with improving the performance of a database that experiences heavy read and write operations. How would you balance the use of indexing to improve read performance while minimizing the impact on write performance?
- Add Indexes to All Columns for Faster Reads
- Use Covering Indexes for Frequently Queried Columns
- Implement Partitioned Tables to Isolate Write-Intensive Data
- Regularly Rebuild All Indexes for Maximum Performance
To balance the use of indexing in a database with heavy read and write operations, it's crucial to use Covering Indexes for frequently queried columns. These indexes include all the necessary data for the query, reducing the need to access the main table. Implementing Partitioned Tables can isolate write-intensive data from read-intensive data, improving write performance. Adding indexes to all columns and regularly rebuilding all indexes can lead to unnecessary overhead and hinder write performance.
Which method in Express.js is used to serve static files?
- app.static()
- app.useStatic()
- app.serveStatic()
- app.use()
In Express.js, the app.use(express.static()) method is used to serve static files. This method allows you to specify a directory from which Express should serve static assets like images, CSS, and JavaScript. The other options are not valid methods for serving static files in Express.
In Express.js, the ______ method is commonly used to protect routes and ensure that only authenticated users can access them.
- authenticate
- secure
- authorize
- validate
In Express.js, the authorize method is commonly used to protect routes and ensure that only authenticated users can access them. This is often achieved through middleware functions that check for authentication and authorization before allowing access. The other options may not be standard methods for this purpose in Express.js.
When connecting to a SQL database in Node.js, the ______ method is commonly used to execute SQL queries.
- query()
- execSQL()
- runQuery()
- execute()
When connecting to a SQL database in Node.js, the query() method is commonly used to execute SQL queries. This method is provided by most SQL database libraries for Node.js and allows you to send SQL queries to the database. Options 2, 3, and 4 are not standard methods for executing SQL queries in Node.js.
How can you implement inheritance between two objects in JavaScript?
- Prototypal Inheritance
- Object Composition
- Class Inheritance
- Functional Inheritance
In JavaScript, inheritance can be implemented through Prototypal Inheritance. Objects can inherit properties and methods from other objects by setting their prototype. The other options describe alternative approaches to code reuse and object creation but don't involve direct inheritance.
In Node.js, which method is used to establish a connection to a MongoDB database?
- connectToMongo()
- openConnection()
- mongoose.connect()
- establishMongoDBConnection
In Node.js, the method used to establish a connection to a MongoDB database is mongoose.connect(). Mongoose is a widely used Node.js library for MongoDB that provides an elegant way to define data schemas and interact with MongoDB. The other options do not represent the standard way to connect to a MongoDB database in Node.js.
In a token-based authentication system, using a ______ approach helps in reducing the risk of token interception and replay attacks.
- Stateless
- Stateful
- Hybrid
- Cookie-based
In a token-based authentication system, a "stateless" approach is used to reduce the risk of token interception and replay attacks. Stateful approaches require server-side storage, while stateless approaches are based on self-contained tokens, which do not rely on server-side storage, making them more secure.