DBMS
Complete Worked Normalisation: Unnormalised to BCNF
One realistic table taken all the way from unnormalised form through 1NF, 2NF, 3NF and BCNF, with every dependency, key and decomposition shown at eac...
#DBMS Practice
Problem sets and worked exercises.
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DBMS
Equivalence of FD Sets and Minimal Cover
Two dependency sets are equivalent when each implies the other. A minimal cover is the smallest equivalent set, computed in three steps, and it is wha...
DBMS
Finding All Candidate Keys of a Relation
A reliable method for finding every candidate key: classify attributes by where they appear in the dependencies, build a compulsory core, then extend...
DBMS
Attribute Closure, Step by Step
The closure of an attribute set is everything it determines. Computing it is a short mechanical loop, and it is the single tool used to find keys, tes...
DBMS
ER Design Project: E-commerce System
An e-commerce database covering customers, products, carts, orders and payments, including why an order line must copy the price it was sold at rather...
DBMS
ER Design Project: Library System
A library database that separates a title from a physical copy, models issue and return correctly, and shows why the obvious single book table quietly...
DBMS
ER Design Project: Banking System
A banking database with a generalisation hierarchy for account types, a many to many customer to account relationship, and a transaction model that ne...
DBMS
ER Design Project: Hospital Database
A hospital database designed end to end, including a weak entity for prescription lines, a ternary relationship for treatment, and the privacy decisio...
DBMS
ER Design Project: College Database
A complete college database designed from a written requirement: entities, attributes, relationships, cardinality, participation, the ER diagram and t...