How does a distributed file system differ from a traditional file system?
- Higher performance due to local disk access
- Increased data security with centralized storage
- Scalability and fault tolerance through multiple servers
- Single point of failure
Distributed file systems use multiple servers to store and manage files, offering scalability and fault tolerance. In contrast, traditional file systems often rely on a single server, which can become a bottleneck and a single point of failure. This fundamental difference impacts scalability, fault tolerance, and overall system resilience.
What SQL keyword is used to retrieve data from a database?
- FETCH
- FILTER
- SEARCH
- SELECT
The correct SQL keyword used to retrieve data from a database is SELECT. This keyword is followed by specific columns or a wildcard (*) to indicate all columns that should be retrieved from a table or tables in the database. Using SELECT is fundamental in SQL as it forms the basis of querying data from databases.
Which normal form allows multi-valued dependencies to be removed?
- First Normal Form (1NF)
- Fourth Normal Form (4NF)
- Second Normal Form (2NF)
- Third Normal Form (3NF)
Fourth Normal Form (4NF) is the normal form that allows multi-valued dependencies to be removed. 4NF is an extension of third normal form (3NF) and deals specifically with situations where there are multiple independent multi-valued dependencies between attributes. By decomposing the table into smaller tables and ensuring each table has a single theme, 4NF helps in removing such complex dependencies and reducing data redundancy.
Which data structure is typically used for binary search?
- Array
- Linked List
- Sorted Array
- Stack
Binary search is typically performed on a sorted array. The reason for this is that binary search requires the elements to be in sorted order to efficiently divide and conquer the search space, reducing the time complexity to O(log n) compared to O(n) for linear search in an unsorted array.
In CSS, the ___________ property is used to control the appearance of text decorations such as underline and overline.
- font-style
- font-variant
- text-decoration
- text-transform
The text-decoration property in CSS is used to control the appearance of text decorations such as underline, overline, line-through, and blink. This property is commonly used to style links and text decorations.
The ________ layer of virtualization abstracts physical hardware resources for efficient utilization.
- Hypervisor
- Container
- Application
- Hardware
The correct option is "Hypervisor." The hypervisor layer is responsible for abstracting physical hardware resources such as CPU, memory, and storage, allowing multiple virtual machines (VMs) to share the underlying physical resources efficiently. This abstraction enables better resource utilization and flexibility in managing virtualized environments.
Memory ___________ is a technique used to rearrange memory contents to place all free memory together.
- Allocation
- Compaction
- Fragmentation
- Paging
Memory compaction is a technique used in memory management to reduce fragmentation by rearranging memory contents to place all free memory together in contiguous blocks. This helps in maximizing the available memory for allocating new processes or data structures, especially in systems where memory fragmentation can lead to inefficient memory usage.
Explain the concept of spanning tree protocol (STP) and its role in preventing network loops.
- STP elects a root bridge to serve as a reference point for path calculations and topology stability.
- STP operates at Layer 3 of the OSI model and prioritizes traffic based on VLAN configurations.
- STP uses BPDU messages to exchange information between switches and determine the best path to the root bridge.
- Spanning Tree Protocol (STP) prevents network loops by blocking redundant paths in a switched network.
STP is vital for ensuring network stability and preventing broadcast storms caused by looping paths in Ethernet networks. By intelligently blocking redundant links while maintaining alternative paths, STP maintains a loop-free topology, optimizing network performance and reliability.
In a cloud storage system, you need to implement file versioning to track changes made by different users. How would you approach this using file system techniques?
- Employ delta encoding techniques to store only the changes made between file versions, reducing storage overhead.
- Implement a version control system within the file system, enabling users to track changes, merge modifications, and maintain a history of file versions.
- Use metadata attributes within the file system to track version history, timestamps, and user identifiers for each modification made to a file.
- Utilize snapshot technology to create copies of files at different points in time, allowing users to revert to previous versions if needed.
Implementing file versioning in a cloud storage system can be achieved through various techniques. Using metadata attributes within the file system to track version history, timestamps, and user identifiers helps maintain a history of modifications. This approach is more efficient than creating copies of entire files or using delta encoding, as it provides a clear record of changes while minimizing storage overhead. Snapshot technology and version control systems are also effective but may involve additional complexities compared to metadata-based version tracking within the file system.
In distributed database systems, ensuring ___________ can be challenging due to network failures.
- Consistency
- Connectivity
- Compatibility
- Concurrency
The correct option is "Connectivity." In distributed database systems, maintaining connectivity among different nodes and ensuring uninterrupted communication is a significant challenge. Network failures, latency issues, and bandwidth constraints can all impact the connectivity of distributed databases, affecting data access and consistency across the system. Overcoming these challenges requires robust networking protocols and fault-tolerant architectures.