Database Management System Semester 1 Quiz
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Questions and Answers

Which type of user interacts with the system using a database query language?

  • Naive users
  • Sophisticated users (correct)
  • Specialized users
  • System administrators

Who is primarily responsible for the design and use of the database in an organization?

  • Database Administrator (correct)
  • Database User
  • Database Programmer
  • Data Analyst

What is the primary characteristic of a hierarchical model?

  • Stores data in rows and columns
  • Organizes data into a tree-like structure (correct)
  • Represents data as objects
  • Uses network links to connect records

Which type of user is described as having very little knowledge of the database system?

<p>Clerk (C)</p> Signup and view all the answers

What does a database model define?

<p>How data can be accessed and updated (C)</p> Signup and view all the answers

Which of the following is NOT one of the commonly recognized types of database models?

<p>Distributed Model (A)</p> Signup and view all the answers

What role does a DBA play concerning an organization's database?

<p>Providing technical support and managing database phases (A)</p> Signup and view all the answers

Which model is best known for using a table-based format?

<p>Relational Model (A)</p> Signup and view all the answers

What does physical data independence allow in a database system?

<p>Modifying the physical storage without altering the conceptual view (C)</p> Signup and view all the answers

Which statement is true regarding logical data independence?

<p>It facilitates modifications at the conceptual schema without changes in application programs. (D)</p> Signup and view all the answers

What is a key feature of the 3-tier architecture?

<p>It separates user interfaces, application logic, and data storage. (A)</p> Signup and view all the answers

What resides at the database tier in a 3-tier architecture?

<p>The database along with its query processing languages (B)</p> Signup and view all the answers

Which of the following describes a challenge with logical data independence?

<p>It makes it difficult to alter the external view. (B)</p> Signup and view all the answers

What is a characteristic of physical data independence?

<p>It allows changes without impacting the conceptual schema. (A)</p> Signup and view all the answers

In which tier does the application server reside in a 3-tier architecture?

<p>Application tier (B)</p> Signup and view all the answers

What is a fundamental aspect of data independence?

<p>Application programs are unaffected by changes in the database structure. (C)</p> Signup and view all the answers

What does the term 'anomaly' refer to in the context of a database management system?

<p>Inconsistency in the data pattern (D)</p> Signup and view all the answers

What causes anomalies to occur in a database?

<p>Storage of all data in a single table (D)</p> Signup and view all the answers

Which of the following describes an updation anomaly?

<p>Inconsistency arising from due updates to some rows (C)</p> Signup and view all the answers

What process is used to remove anomalies in a database?

<p>Normalization (B)</p> Signup and view all the answers

Which of the following can lead to reduced integrity in a database?

<p>High levels of data redundancy (A)</p> Signup and view all the answers

Which of the following is NOT a type of anomaly described in the context?

<p>Insert Anomaly (A)</p> Signup and view all the answers

Why is it important to manage anomalies in a database?

<p>To ensure the integrity of the database (B)</p> Signup and view all the answers

In a poorly constructed table, what is the primary consequence?

<p>Increased likelihood of data anomalies (A)</p> Signup and view all the answers

What type of cardinality mapping is described by a student having only one student ID and vice versa?

<p>One-to-One (B)</p> Signup and view all the answers

In a One-to-Many cardinality, how can you describe the relationship from set 1 to set 2?

<p>One entity in set 1 can relate to multiple entities in set 2. (D)</p> Signup and view all the answers

What does Many-to-One cardinality imply in terms of relationships?

<p>Multiple entities in set 1 can relate to one entity in set 2. (B)</p> Signup and view all the answers

In a Many-to-Many cardinality relationship, how are entities associated?

<p>Multiple entities from both sets can relate to each other. (C)</p> Signup and view all the answers

Which statement best describes the role of keys in a relational database?

<p>They are used to uniquely identify records and establish relationships. (B)</p> Signup and view all the answers

Which cardinality represents a relationship where one entity can relate to multiple others, but only a single entity can relate back?

<p>Many-to-One (D)</p> Signup and view all the answers

How can the One-to-Many cardinality be effectively illustrated?

<p>By showing a single doctor treating multiple patients. (D)</p> Signup and view all the answers

What is the notation used to represent Many-to-Many cardinality?

<p>M:N (D)</p> Signup and view all the answers

What command is used to restore a database to its original state since the last COMMIT?

<p>ROLLBACK (C)</p> Signup and view all the answers

Which of the following is true about DML statements?

<p>They can be reverted without a COMMIT. (B)</p> Signup and view all the answers

What is the purpose of the SAVEPOINT command?

<p>To create a point to which a rollback can occur. (B)</p> Signup and view all the answers

Which statement correctly summarizes the use of the GRANT command?

<p>It provides users with access privileges to the database. (B)</p> Signup and view all the answers

What effect does the COMMIT command have on a transaction?

<p>It saves all operations made in the current transaction. (A)</p> Signup and view all the answers

Which SQL statement would you use to select only specific columns from a table?

<p>SELECT column1, column2 FROM table_name; (D)</p> Signup and view all the answers

What is indicated by the term TCL in database terminology?

<p>Transaction Control Language (B)</p> Signup and view all the answers

Which SQL statement includes a mathematical operation on a column?

<p>SELECT Sal, Sal * 0.1 FROM Employees; (C)</p> Signup and view all the answers

Study Notes

Relational Database Design

  • Anomaly refers to inconsistencies in relational tables during operations, arising from redundant data and poor table construction.
  • Database integrity is compromised due to anomalies, necessitating normalization to eliminate these issues.
  • Normalization involves splitting and joining tables to design a more efficient database structure.

Anomalies in Databases

  • Types of anomalies include:
    • Updation/Update Anomaly: Inconsistencies during data updates; requires updating all affected rows (e.g., multiple entries for the same worker).

Data Independence

  • Physical Data Independence: Allows modifications to physical storage without changing the conceptual or external views; enhances performance and is easier to achieve.
  • Logical Data Independence: Involves changes to the conceptual schema without altering application programs; more complex to achieve.

Database System Architecture

  • The 3-tier architecture is widely used, consisting of:
    • Database (Data) Tier: Contains the database and query processing languages.
    • Application (Middle) Tier: Houses application servers that access the database.
    • User (Client) Tier: Where user applications operate.

User Types

  • Sophisticated Users: Interact using database query languages without programming.
  • Specialized Users: Create specialized applications not fitting traditional data processing.
  • Naive Users: Have minimal database knowledge and interact using predefined application programs (e.g., bank clerks).

Database Administrator (DBA)

  • Controls design and utilization of the database.
  • Provides technical support throughout the database lifecycle (design, development, testing, operation).
  • Knowledge of database technology is vital; business understanding enhances effectiveness.

Data Models

  • Defines the logical structure of databases; the most common model is the relational model.
  • Types of database models include:
    • Hierarchical Model: Tree-like structure with single parent-child relationships.
    • Network Model: More complex relationships than hierarchical.
    • Entity-Relationship Model: Represents data entities and their relationships.
    • Relational Model: Uses tables for data representation.
    • Object-oriented Database Model: Incorporates object-oriented programming concepts into database design.

Cardinalities

  • Types of cardinality relationships:
    • One-to-One: Each entity in set one associates with one entity in set two.
    • One-to-Many: A single entity in set one relates to multiple entities in set two (e.g., a hospital to multiple compounders).
    • Many-to-One: Multiple entities in set one relate to a single entity in set two (e.g., patients to a doctor).
    • Many-to-Many: Entities in both sets can relate to multiple entities in the opposite set.

Keys in Databases

  • Keys uniquely identify records or rows in a table and establish relationships between tables.

Transaction Control Language (TCL)

  • Commands include:
    • GRANT: Assigns user access privileges to the database.
    • REVOKE: Withdraws previously granted privileges.
    • COMMIT: Saves changes made by Data Manipulation Language (DML) statements.
    • ROLLBACK: Restores the database to its state since the last COMMIT.
    • SAVEPOINT: Marks a point in a transaction for potential rollback.

SQL Basics

  • The SELECT statement retrieves records from tables. Syntax includes optional clauses for conditions, grouping, and ordering.
  • Example SQL queries:
    • Retrieve all columns: SELECT * FROM dept;
    • Select specific columns: SELECT LOC, DEPTNO FROM DEPT;
    • Conditional selections: SELECT name, city FROM suppliers WHERE supplier_id > 1000;

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Description

Test your knowledge on the Database Management System for Semester 1. This quiz covers key concepts and topics from UNIT 3 of the course. Prepare to demonstrate your understanding of database theory and its practical applications.

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