Database Systems

Description: This quiz covers fundamental concepts, data models, database design, query processing, and transaction management in database systems.
Number of Questions: 15
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Tags: database systems data models sql normalization transactions
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Which data model represents data in the form of objects and their relationships?

  1. Relational Model

  2. Network Model

  3. Hierarchical Model

  4. Object-Oriented Model


Correct Option: D
Explanation:

The object-oriented data model represents data in the form of objects, which are entities with attributes and methods. Objects are linked together through relationships, forming a network of interconnected objects.

What is the process of organizing data into a logical structure for efficient storage and retrieval called?

  1. Normalization

  2. Denormalization

  3. Indexing

  4. Clustering


Correct Option: A
Explanation:

Normalization is the process of organizing data into a logical structure that minimizes redundancy and ensures data integrity. It involves dividing data into tables and establishing relationships between them based on common attributes.

Which SQL statement is used to retrieve data from a database?

  1. SELECT

  2. INSERT

  3. UPDATE

  4. DELETE


Correct Option: A
Explanation:

The SELECT statement is used to retrieve data from a database. It allows you to specify the columns and rows to be retrieved, as well as filter and sort the results.

What is the term for a collection of related data stored in a database?

  1. Table

  2. Row

  3. Column

  4. Record


Correct Option: A
Explanation:

A table is a collection of related data stored in a database. It consists of rows and columns, where each row represents a record and each column represents a field or attribute of that record.

Which database system component is responsible for managing concurrent access to data and ensuring data integrity?

  1. Query Processor

  2. Transaction Manager

  3. Storage Manager

  4. Buffer Manager


Correct Option: B
Explanation:

The transaction manager is responsible for managing concurrent access to data and ensuring data integrity. It ensures that transactions are executed atomically, consistently, isolated, and durably (ACID properties).

What is the process of breaking down a complex query into smaller, more manageable subqueries called?

  1. Query Optimization

  2. Query Decomposition

  3. Query Transformation

  4. Query Rewriting


Correct Option: B
Explanation:

Query decomposition is the process of breaking down a complex query into smaller, more manageable subqueries. This helps improve query performance by reducing the number of accesses to the database and minimizing the amount of data that needs to be processed.

Which database system component is responsible for managing the physical storage of data on disk?

  1. Query Processor

  2. Transaction Manager

  3. Storage Manager

  4. Buffer Manager


Correct Option: C
Explanation:

The storage manager is responsible for managing the physical storage of data on disk. It allocates space for data files, manages free space, and handles data placement and retrieval.

What is the term for a temporary storage area in memory where frequently accessed data is stored to improve query performance?

  1. Cache

  2. Buffer

  3. Pool

  4. Heap


Correct Option: B
Explanation:

A buffer is a temporary storage area in memory where frequently accessed data is stored to improve query performance. It acts as a bridge between the main memory and the disk, reducing the number of disk accesses and speeding up data retrieval.

Which database system component is responsible for parsing and validating SQL statements?

  1. Query Processor

  2. Transaction Manager

  3. Storage Manager

  4. Buffer Manager


Correct Option: A
Explanation:

The query processor is responsible for parsing and validating SQL statements. It converts the SQL statement into an internal representation, optimizes the query plan, and executes the query against the database.

What is the term for a unique identifier assigned to each row in a table?

  1. Primary Key

  2. Foreign Key

  3. Candidate Key

  4. Alternate Key


Correct Option: A
Explanation:

A primary key is a unique identifier assigned to each row in a table. It ensures that each row can be uniquely identified and serves as the basis for establishing relationships between tables.

Which database system component is responsible for maintaining the consistency of data in the database?

  1. Query Processor

  2. Transaction Manager

  3. Storage Manager

  4. Buffer Manager


Correct Option: B
Explanation:

The transaction manager is responsible for maintaining the consistency of data in the database. It ensures that transactions are executed atomically, consistently, isolated, and durably (ACID properties).

What is the term for a logical connection between two tables based on a common column or attribute?

  1. Primary Key

  2. Foreign Key

  3. Candidate Key

  4. Alternate Key


Correct Option: B
Explanation:

A foreign key is a logical connection between two tables based on a common column or attribute. It ensures that the data in the child table is related to the data in the parent table, maintaining referential integrity.

Which database system component is responsible for managing the allocation and deallocation of memory for data structures?

  1. Query Processor

  2. Transaction Manager

  3. Storage Manager

  4. Buffer Manager


Correct Option: D
Explanation:

The buffer manager is responsible for managing the allocation and deallocation of memory for data structures. It allocates buffers for data pages and manages the replacement of pages in the buffer pool when necessary.

What is the term for a collection of related tables in a database?

  1. Schema

  2. Catalog

  3. Database

  4. Instance


Correct Option: A
Explanation:

A schema is a collection of related tables in a database. It defines the structure of the database, including the names of the tables, the columns within each table, and the relationships between the tables.

Which database system component is responsible for optimizing the execution of queries?

  1. Query Processor

  2. Transaction Manager

  3. Storage Manager

  4. Buffer Manager


Correct Option: A
Explanation:

The query processor is responsible for optimizing the execution of queries. It generates an efficient query plan that minimizes the cost of executing the query, taking into account factors such as the size of the tables, the availability of indexes, and the type of query being executed.

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