IB Computer Science HL · Year 2 · Lesson 43
Relational databases + database schemas
Databases organize persistent data so that it can be stored, related and accessed consistently. Database design moves from real-world entities to schemas, keys, relationships and normalized tables.
Paper 150 minutesA3.1.1 · A3.2.1
Use Next or the arrow keys.
Today’s targets
What you need to be able to do
2 / 7
- ExplainThe features, benefits and limitations of a relational database
- DescribeDatabase schemas
A3.1.1A3.2.1
Paper 1 lensMatch the depth of every response to the command term. Previously learned content can move quickly, but retrieval must still be accurate.
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Retrieve
Rapid Recall Deck
3 / 7
Say the answer aloud before flipping. Mark secure knowledge quickly and spend time on the gaps.
- What makes a database relational?: Data is organized into related tables whose records can be connected using keys and defined relationships.
- What is the purpose of a primary key?: It uniquely identifies each record in a table.
- What is the purpose of a foreign key?: It stores a value that references a key in another table, creating a relationship between records.
- What is a composite key?: A key formed from two or more attributes/fields that together uniquely identify a record.
- What are major benefits of relational databases?: Examples include data consistency/integrity, reduced duplication, concurrency control, reliable transactions, security, scalability, and powerful retrieval.
- What are conceptual, logical, and physical schemas?: Conceptual schema describes the high-level data model; logical schema defines organized structures/relationships; physical schema describes how the data is actually stored and accessed.
- What are common limitations of relational databases?: Rigid schemas, design complexity, challenges with hierarchical or unstructured data, object-relational impedance mismatch, and scalability issues for some very large data workloads.
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A3.1.1 + A3.2.1 · Learn
Core knowledge and application
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A3.1.1Explain
The features, benefits and limitations of a relational database
Databases organize persistent data so that it can be stored, related and accessed consistently.
Exam moveGive the mechanism or relationship and make the reasons/causes explicit.
Required detail 1Features: composite keys, foreign keys, primary keys, relationships, tables
Required detail 2Benefits of databases: community support, concurrency control, data consistency, data integrity, data retrieval, reduced data duplication, reduced redundancy, reliable transaction processing, scalability, security features
Required detail 3Limitations of databases: “big data” scalability issues, design complexity, hierarchical data handling, rigid schema, object-relational impedance mismatch, unstructured data handling
Explain it without notes
Explain: The features, benefits and limitations of a relational database in the context of a school library storing users, books and loans.
- Features: composite keys, foreign keys, primary keys, relationships, tables
- Benefits of databases: community support, concurrency control, data consistency, data integrity, data retrieval, reduced data duplication, reduced redundancy, reliable transaction processing, scalability, security features
- Limitations of databases: “big data” scalability issues, design complexity, hierarchical data handling, rigid schema, object-relational impedance mismatch, unstructured data handling
A3.2.1Describe
Database schemas
Database design moves from real-world entities to schemas, keys, relationships and normalized tables.
Exam moveGive a detailed, accurate account of what happens or what something is like.
Required detail 1Conceptual schema, logical schema, physical schema
Required detail 2Abstract definitions of the data structure and organization of the data at different levels
Explain it without notes
Describe: Database schemas in the context of a library database being redesigned to reduce redundancy and anomalies.
- Conceptual schema, logical schema, physical schema
- Abstract definitions of the data structure and organization of the data at different levels
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Apply
Transfer to a new scenario
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ScenarioA school library storing users, books and loans needs a design or technical decision related to today’s topic. Explain what matters and why.
- Features: composite keys, foreign keys, primary keys, relationships, tables
- Benefits of databases: community support, concurrency control, data consistency, data integrity, data retrieval, reduced data duplication, reduced redundancy, reliable transaction processing, scalability, security features
- Conceptual schema, logical schema, physical schema
- Abstract definitions of the data structure and organization of the data at different levels
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Exam lens
Paper 1 practice
6 / 7
Build the response before checking notesUse precise terminology and match the required depth.
- Explain: The features, benefits and limitations of a relational database in the context of a school library storing users, books and loans.
- Describe: Database schemas in the context of a school library storing users, books and loans.
Self-checkAnswer the exact command term. For explain, include mechanism/reason; for compare, pair criteria; for discuss/evaluate/justify, build supported reasoning and a conclusion.
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Homework
Finish the learning cycle
7 / 7
IA — main task
Complete Criterion E and final IA quality checks. Evaluate the product against success criteria and propose specific, feasible improvements.
Syllabus — short
Complete a short Paper 1 retrieval task; keep the IA as the main workload.
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End of Lesson 43.