Which AWS service allows users to define and provision infrastructure resources using code?
- AWS CloudFormation
- AWS EC2
- AWS Lambda
- AWS S3
AWS CloudFormation is the AWS service that allows users to define and provision infrastructure resources using code. It enables the creation and management of AWS resources through templates, facilitating infrastructure as code practices.
_______ is a data format commonly used for representing resources in RESTful APIs.
- HTML (Hypertext Markup Language)
- JSON (JavaScript Object Notation)
- XML (eXtensible Markup Language)
- YAML (YAML Ain't Markup Language)
JSON (JavaScript Object Notation) is a data format commonly used for representing resources in RESTful APIs. It provides a lightweight and easy-to-read format for data exchange between the client and server.
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.
A _______ is a data structure that consists of a collection of nodes and edges.
- Graph
- Heap
- Queue
- Tree
A graph is a data structure that consists of a collection of nodes and edges. Nodes represent entities, and edges represent relationships between those entities.
What is the difference between a JOIN and a UNION in SQL?
- JOIN combines rows from two or more tables based on a related column
- JOIN is used for vertical merging
- UNION combines the results of two or more SELECT statements
- UNION is used for horizontal merging
In SQL, a JOIN combines rows from two or more tables based on a related column, while a UNION combines the results of two or more SELECT statements. JOIN operates vertically by merging rows, while UNION operates horizontally by combining result sets.
The command "git reflog" displays a _______ of actions that have been taken in the repository.
- Catalog
- Log
- Record
- Timeline
The command "git reflog" displays a log of actions that have been taken in the repository. It provides a reference log, showing the history of HEAD movements, making it useful for recovering lost commits or branches.
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.
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.
_______ 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.
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.
_______ 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.
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.