Stage 5: Derive the logical data model
Knobit of Data modelling · K-563 · Knowledge
Explains lossless-join decomposition
What it means
A split is lossless only if the shared attributes are a key of at least one part.
How it is assessed
Decides for sample decompositions whether joining back produces spurious rows
Builds on
- Explains candidate key and prime attributeK-552 · Knowledge
Needed by
- Recognises a lossy decompositionK-514 · Skill
- Decomposes an entity along a functional dependency without lossK-533 · Skill
- Explains vertical and horizontal partitioning of tablesK-660 · Knowledge