Section 1: Database Management Systems (DBMS) Fundamentals
What is the formal definition of a Database Management System (DBMS)?
System software used for defining, creating, and manipulating a database.
What does the term “Data Management” encompass within a database context?
The process of organizing and maintaining data within a database to deliver necessary information.
What is a Data Dictionary?
A set of data containing metadata, which is defined as data about other data within a database.
Define “Data Modelling.”
The analysis and definition of data structures required in a database, which results in the creation of a data model.
What is a Logical Schema?
A data model specific to a database that remains independent of the DBMS used for its construction.
Define “Access Rights” in a database environment.
The specific permissions granted to users for accessing, modifying, or deleting data.
What is the Developer Interface?
A DBMS feature providing commands that allow developers to define, create, and manipulate the database.
What is Structured Query Language (SQL)?
The standard language used for defining and modifying data within relational databases.
What is the primary role of the Query Processor?
A DBMS feature responsible for processing and executing SQL-based queries.
Section 2: Addressing File-Based Limitations
How does a DBMS address the issue of Data Redundancy found in file-based systems?
By linking tables so that most data is stored only once; however, foreign keys are an exception as they must be stored in multiple tables to create links.
How does a DBMS handle inappropriate deletion of linked items?
The system flags errors if a user attempts to delete linked items, such as foreign key records, inappropriately.
How is “Data Inconsistency” resolved by a DBMS?
By storing most data items only once, updates become universally accessible across all applications, ensuring consistency.
What is “Data Dependency” in file-based systems?
A situation where changes to the data structure impact all associated applications.
How does a DBMS achieve “Data Independence”?
It decouples data from specific applications, allowing structural changes (like adding fields) to be managed with minimal impact on unrelated applications.
Section 3: Data Dictionary and Logical Schema
What metadata is typically stored in a Data Dictionary?
Definitions for tables, attributes, relationships between tables, indexing details, and validation rules.
[Past Exam Q&A adds:]
From exam Q&A, a data dictionary specifically contains:
• Field / attribute names
• Table name(s)
• Data types
• Primary keys // foreign keys
• Validation rules
• Relationships
How does a Data Dictionary enhance data integrity?
By ensuring the accuracy, completeness, and consistency of the data through defined rules.
What is the focus of a Logical Schema?
It represents how data is logically structured, defining what data is stored, entity relationships, and constraints without detailing physical storage.
What are the three main differences between a Data Dictionary and a Logical Schema?
- Definition: Metadata vs. conceptual design.
- Scope: Table attributes vs. table relationships.
- Format: Tabular structure vs. ER diagrams/textual representation.
Section 4: Security and Developer Tools
List five security measures provided by a DBMS.
- Usernames and Passwords.
- Access Rights.
- Automated Back-ups.
- Data Encryption.
- Audit Trails.
What are Audit Trails used for?
To log user actions for monitoring data access and modifications.
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Records and ADTs (Practical) #143
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Computational Thinking (Practical) #119
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