Which of the following database models organizes data in a tree-like structure with parent-child relationships?
💡 Explanation
The hierarchical model uses a parent-child relationship in a top-down tree structure to represent data.
In a relational database model, data is represented in the form of:
💡 Explanation
The relational model stores data in rows and columns, collectively referred to as tables or relations.
Which NoSQL database type is best suited for storing data as documents, typically in JSON or BSON format?
💡 Explanation
Document databases, such as MongoDB, store data in flexible document formats like JSON.
Which characteristic is a primary advantage of NoSQL databases over traditional relational databases?
💡 Explanation
NoSQL databases are designed for high-speed, horizontal scalability (sharding) across multiple servers.
In a hierarchical model, what is a primary limitation regarding data relationship types?
💡 Explanation
The hierarchical model strictly enforces one-to-many relationships, making many-to-many relationships difficult to represent.
Which NoSQL database type represents data as nodes, edges, and properties?
💡 Explanation
Graph databases specialize in representing highly interconnected data using nodes and edges.
The 'CAP Theorem' states that a distributed database can only provide two of three guarantees. What are these three guarantees?
💡 Explanation
CAP stands for Consistency, Availability, and Partition Tolerance.
Which database model is specifically designed to handle massive amounts of unstructured data and high-velocity write operations?
💡 Explanation
NoSQL is built for Big Data applications requiring schema flexibility and high write throughput.
What is the primary role of a 'Schema' in a relational database compared to a NoSQL database?
💡 Explanation
Relational databases are schema-on-write (rigid), whereas NoSQL is often schema-on-read (flexible).
Which of the following is considered a 'Wide-column store' NoSQL database?
💡 Explanation
Apache Cassandra is a classic example of a wide-column store designed for high availability and scalability.
Which property of a relational database ensures that all transactions are processed reliably, maintaining database integrity even in the event of a system failure?
💡 Explanation
ACID (Atomicity, Consistency, Isolation, Durability) is the set of properties that guarantee reliable processing of database transactions.
What is the primary drawback of a hierarchical database model when dealing with M:N (many-to-many) relationships?
💡 Explanation
Hierarchical models are restricted to 1:N relationships, making M:N relationships difficult to represent without duplicating data or creating complex structures.
In the context of the CAP theorem, which database model typically prioritizes 'Availability' and 'Partition Tolerance' (AP) to handle massive distributed datasets?
💡 Explanation
NoSQL databases often follow the BASE model (Basically Available, Soft state, Eventual consistency) prioritizing availability and partitioning over strict consistency.
Which NoSQL category uses a hash table to store data where each key is associated with one specific value?
💡 Explanation
Key-Value stores are the simplest form of NoSQL databases, functioning as a associative array or dictionary.
Which operation is commonly used in Relational Databases to combine rows from two or more tables based on a related column?
💡 Explanation
JOIN is the standard relational algebra operation to retrieve data from multiple tables that share a common field.
Which term describes the 'horizontal scaling' of NoSQL databases, where more nodes are added to the cluster to handle load?
💡 Explanation
Sharding is the process of partitioning data across multiple servers to achieve horizontal scalability.
What type of schema is typically enforced in NoSQL databases, offering flexibility for evolving data requirements?
💡 Explanation
NoSQL databases are often schema-less or dynamic, meaning they do not require a pre-defined structure before inserting data.
Which of the following is a common real-world use case for Graph Database models?
💡 Explanation
Graph databases excel at managing highly connected data, such as social networks, where relationships between entities are as important as the entities themselves.
Which database model stores data in a series of records, where each record has a pointer to its parent record?
💡 Explanation
The hierarchical model uses a parent-child structure where records are linked through pointers in a tree-like hierarchy.
In comparison to RDBMS, what is the main goal of using a Wide-Column store like Cassandra?
💡 Explanation
Wide-Column stores are designed for high-performance writes and massive scalability across distributed clusters, unlike RDBMS which emphasizes data consistency through joins.