What are some key criteria for evaluating the quality of a pull request?
- Code complexity and design principles
- Code readability and maintainability
- Git branch history
- Test coverage and performance
Evaluating the quality of a pull request involves considering code readability, maintainability, adherence to design principles, and overall code complexity. These factors contribute to a robust and maintainable codebase.
_______ is the ability of an object to take on many forms in OOP.
- Abstraction
- Encapsulation
- Inheritance
- Polymorphism
Polymorphism is the ability of an object to take on many forms. In object-oriented programming (OOP), it allows objects of different types to be treated as objects of a common type, providing flexibility and extensibility in code design.
In a distributed database system, how would you approach query optimization to minimize network latency and improve overall performance?
- Implement only vertical partitioning, Optimize queries centrally, Decrease node communication, Disable encryption on the network
- Implement sharding and partitioning, Use asynchronous communication, Optimize queries locally on each node, Increase the bandwidth of the network
- Increase network latency intentionally, Use only synchronous communication, Disable query caching, Randomly distribute data across nodes
- Use a single centralized database, Minimize the number of nodes, Decrease the network bandwidth, Increase the size of each query
In a distributed database system, optimizing queries involves implementing sharding, partitioning, and using asynchronous communication to minimize network latency. Optimizing queries locally on each node is essential for efficient distributed query processing.
_______ migration involves moving data from one storage system to another without any downtime.
- Live
- Non-disruptive
- Seamless
- Zero-Downtime
Zero-Downtime migration refers to the process of moving data from one storage system to another without any disruption or downtime in services. This ensures continuous operations during the migration.
You're tasked with optimizing a query that retrieves data from a large table. Outline the steps you would take to analyze and optimize the query.
- Analyze query execution plan, Identify and create necessary indexes, Optimize SQL queries, Monitor system resources
- Backup and restore the entire database, Use only subqueries, Disable query caching, Modify the network configuration
- Rebuild the entire database, Delete unnecessary records, Increase server memory, Change database schema
- Use NoSQL instead of SQL, Change server hardware, Reduce database security, Update all records in the table
To optimize a query, you would analyze its execution plan, identify and create necessary indexes, and optimize the SQL queries. Monitoring system resources is crucial to ensuring overall performance improvements.
Which method is used to add elements to the end of an array in JavaScript?
- pop()
- push()
- shift()
- splice()
The push() method in JavaScript is used to add elements to the end of an array. It modifies the original array by adding the specified elements.
Which AWS service is used for container orchestration?
- AWS Lambda
- Amazon ECS
- Amazon RDS
- Amazon S3
Amazon ECS (Elastic Container Service) is the AWS service used for container orchestration. It allows users to run, stop, and manage Docker containers on a cluster, making it easier to deploy and scale containerized applications.
Which of the following is a common method to prevent Cross-Site Scripting (XSS) attacks?
- Cross-Site Request Forgery (CSRF)
- Input validation
- Output encoding
- Session hijacking
Output encoding is a common method to prevent Cross-Site Scripting (XSS) attacks. By encoding user-input before displaying it in a web page, potential malicious scripts are neutralized, reducing the risk of XSS vulnerabilities.
Implementing _______ loading allows resources like images and scripts to be loaded asynchronously, improving overall performance.
- Asynchronous
- Parallel
- Sequential
- Synchronous
Asynchronous loading enables resources to load independently of the main page, preventing them from blocking other page elements. This contributes to faster page rendering and improved performance.
What is the purpose of hash tables in data structures?
- Creating a linked list of data elements.
- Efficient data retrieval and storage by mapping keys to array indices using a hash function.
- Sorting elements based on their hash values.
- Storing data in a random order for quick access.
Hash tables are data structures that use a hash function to map keys to array indices, allowing for efficient data retrieval and storage. This structure enables constant-time average-case complexity for common operations like insertions, deletions, and searches.