ACID stands for Atomicity, Consistency, Isolation, and Durability, which are the properties that guarantee reliable processing of database transactions.
Correct Answer: A — Atomicity, Consistency, Isolation, Durability
Q. What does the term 'cardinality' refer to in an ER model?
A.The number of attributes in an entity
B.The number of entities in a relationship
C.The type of data stored in an entity
D.The uniqueness of an entity
Solution
Cardinality refers to the number of entities involved in a relationship.
Correct Answer: B — The number of entities in a relationship
Q. What does the term 'concurrency control' refer to in a DBMS?
A.Managing multiple database connections
B.Ensuring data consistency during simultaneous transactions
C.Optimizing query performance
D.Backing up data
Solution
Concurrency control refers to the management of simultaneous operations on a database without conflicting.
Correct Answer: B — Ensuring data consistency during simultaneous transactions
Q. What does the term 'data latency' refer to in a data warehouse?
A.The speed of data retrieval
B.The time delay between data generation and its availability for analysis
C.The amount of data stored
D.The frequency of data updates
Solution
Data latency refers to the time delay between when data is generated and when it becomes available for analysis in a data warehouse.
Correct Answer: B — The time delay between data generation and its availability for analysis
Q. What does the term 'denormalization' refer to in database design?
A.The process of reducing redundancy
B.The process of increasing redundancy for performance
C.The process of normalizing data
D.The process of creating indexes
Solution
Denormalization refers to the process of increasing redundancy in a database to improve performance, often at the cost of data integrity.
Correct Answer: B — The process of increasing redundancy for performance
Q. What is a common challenge in distributed databases?
A.Data normalization
B.Network latency
C.Data encryption
D.User authentication
Solution
Network latency is a common challenge in distributed databases as it can affect the speed and efficiency of data access and transactions.
Correct Answer: B — Network latency
Q. What is a common consequence of not normalizing a database?
A.Increased data integrity
B.Data redundancy
C.Improved performance
D.Simplified queries
Solution
Not normalizing a database can lead to data redundancy, which can cause inconsistencies and anomalies.
Correct Answer: B — Data redundancy
Q. What is a dimension table in a data warehouse?
A.A table that stores transactional data
B.A table that contains descriptive attributes
C.A table that holds metadata
D.A table that indexes data
Solution
Dimension tables contain descriptive attributes that provide context to the facts stored in the fact tables.
Correct Answer: B — A table that contains descriptive attributes
Q. What is a distributed database?
A.A database that is stored on a single server
B.A database that is spread across multiple locations
C.A database that uses cloud storage
D.A database that is only accessible via the internet
Solution
A distributed database is a database that is spread across multiple locations, which can be on different servers or geographical locations.
Correct Answer: B — A database that is spread across multiple locations
Q. What is a federated database system?
A.A single database managed by one server
B.A collection of autonomous databases that appear as one
C.A database that only stores metadata
D.A database that is only accessible through APIs
Solution
A federated database system is a collection of autonomous databases that appear as one, allowing for distributed data access while maintaining individual database autonomy.
Correct Answer: B — A collection of autonomous databases that appear as one
Q. What is a foreign key in a relational database?
A.A key that uniquely identifies a record
B.A key that links two tables together
C.A key that is used for indexing
D.A key that is automatically generated
Solution
A foreign key is a field (or collection of fields) in one table that uniquely identifies a row of another table.
Correct Answer: B — A key that links two tables together
Q. What is a foreign key?
A.A primary key in another table
B.A unique identifier for a table
C.An attribute that can be null
D.A key used for indexing
Solution
A foreign key is a primary key in another table that establishes a relationship between the two tables.
Correct Answer: A — A primary key in another table
Q. What is a primary key in the context of an ER model?
A.A key that allows for data redundancy
B.A unique identifier for each entity instance
C.A foreign key that links to another table
D.A type of relationship between entities
Solution
A primary key is a unique identifier for each instance of an entity, ensuring that no two instances are the same.
Correct Answer: B — A unique identifier for each entity instance
Q. What is a primary key?
A.A unique identifier for a record
B.A foreign key reference
C.An index for faster searches
D.A type of relationship
Solution
A primary key is a unique identifier for a record in a database table, ensuring that no two records can have the same key value.
Correct Answer: A — A unique identifier for a record
Q. What is a star schema in data warehousing?
A.A type of data normalization
B.A database design with a central fact table and dimension tables
C.A method for indexing data
D.A concurrency control mechanism
Solution
A star schema is a type of database design that consists of a central fact table surrounded by dimension tables, facilitating easier data retrieval.
Correct Answer: B — A database design with a central fact table and dimension tables
Q. What is a transaction in the context of a database management system?
A.A single SQL command
B.A sequence of operations treated as a single unit
C.A backup of the database
D.A method of data retrieval
Solution
A transaction is a sequence of operations that are treated as a single unit of work, ensuring data integrity.
Correct Answer: B — A sequence of operations treated as a single unit
Q. What is a transaction in the context of a database?
A.A single SQL command
B.A sequence of operations treated as a single unit
C.A backup of the database
D.A method of data retrieval
Solution
A transaction is a sequence of operations that are executed as a single unit of work.
Correct Answer: B — A sequence of operations treated as a single unit
Q. What is a weak entity in an ER model?
A.An entity that cannot exist without a strong entity
B.An entity with no attributes
C.An entity that has a composite key
D.An entity that is not related to any other entity
Solution
A weak entity is one that cannot exist without a strong entity.
Correct Answer: A — An entity that cannot exist without a strong entity
Q. What is concurrency control in a DBMS?
A.Managing data redundancy
B.Ensuring data consistency during simultaneous access
C.Optimizing query performance
D.Backing up data
Solution
Concurrency control in a DBMS ensures data consistency during simultaneous access by multiple transactions.
Correct Answer: B — Ensuring data consistency during simultaneous access
Q. What is denormalization?
A.The process of reducing redundancy
B.The process of increasing redundancy
C.The process of normalizing data
D.The process of creating indexes
Solution
Denormalization is the process of increasing redundancy in a database to improve read performance by reducing the number of joins needed.
Correct Answer: B — The process of increasing redundancy
Q. What is normalization in database design?
A.The process of organizing data to reduce redundancy
B.The process of creating a database
C.The process of indexing data
D.The process of backing up data
Solution
Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.
Correct Answer: A — The process of organizing data to reduce redundancy
Q. What is normalization?
A.The process of organizing data
B.The process of backing up data
C.The process of indexing data
D.The process of encrypting data
Solution
Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.
Correct Answer: A — The process of organizing data
Q. What is the main advantage of using an ER model?
A.It is easy to implement in SQL
B.It provides a clear visual representation of data
C.It eliminates the need for normalization
D.It allows for complex queries
Solution
The main advantage of using an ER model is that it provides a clear visual representation of data and relationships.
Correct Answer: B — It provides a clear visual representation of data
Q. What is the main advantage of using indexes in a database?
A.To reduce data redundancy
B.To speed up data retrieval
C.To enforce data integrity
D.To simplify database design
Solution
Indexes are used to speed up data retrieval operations by providing quick access paths to the data.
Correct Answer: B — To speed up data retrieval
Q. What is the main advantage of using indexing in a data warehouse?
A.Increased data redundancy
B.Faster query performance
C.Simplified data modeling
D.Reduced storage requirements
Solution
Indexing improves query performance by allowing the database to find data more quickly, which is crucial in a data warehouse environment.
Correct Answer: B — Faster query performance
Q. What is the main advantage of using indexing in a database?
A.Increases data redundancy
B.Improves data integrity
C.Speeds up data retrieval
D.Simplifies database design
Solution
Indexing improves data retrieval speed by allowing the database to find data more quickly.
Correct Answer: C — Speeds up data retrieval
Q. What is the main goal of concurrency control in a DBMS?
A.To prevent data redundancy
B.To ensure data consistency
C.To improve query performance
D.To manage user access
Solution
The main goal of concurrency control in a DBMS is to ensure data consistency when multiple transactions are executed simultaneously.
Correct Answer: B — To ensure data consistency
Q. What is the main goal of normalization?
A.To increase data redundancy
B.To eliminate data anomalies
C.To improve query performance
D.To simplify database design
Solution
The main goal of normalization is to eliminate data anomalies and ensure data integrity by organizing data efficiently.
