Relational models, keys, normalization, transactions, indexing, SQL and database design. Use this page to understand the concept before attempting focused practice.
Relational model: relations, tuples, attributes and keys.
Normalization: 1NF, 2NF, 3NF and BCNF as tools for reducing update anomalies.
Transactions and ACID: atomicity, consistency, isolation and durability.
SQL: filtering, joins, grouping, subqueries and data-definition/manipulation basics.
Indexing and query performance: understand why an index can speed lookups but adds storage/write cost.
Common exam traps
Confusing candidate key with primary key.
Treating 3NF as a synonym for normalization in general.
Mixing WHERE filtering with HAVING aggregation filtering.
Assuming every index automatically improves every query.
How to study it on ExamCracker
Read the core concepts and examples.
Attempt the focused public practice on the related exam hub.
Review every incorrect answer instead of only checking the score.
Return to the topic before moving to a full-length mock.
Quick check
Quick check: Which normal form is defined by the elimination of partial dependency on a composite candidate key?
A. 1NF
B. 2NF
C. 3NF
D. BCNF
Answer: 2NF Why: Partial dependency is the issue addressed by Second Normal Form. A relation in 2NF is already in 1NF and has no partial dependency of a non-key attribute on part of a candidate key.
Why this page exists
This is a focused learning page, not a keyword-only article. It connects an exam concept to practice, related resources and the broader ExamCracker preparation flow.