C170 - Data Management Applications ALREADY PASSED
First Normal Form - - when all non-key columns depend on the primary key - a table with a primary key is in first normal form - a table with no duplicate rows is in first normal form Second Normal Form - - when all non-key columns depend on the whole primary key - cannot depend on part of a composite primary key - a table with a simple primary key is automatically in second normal form A table with a simple primary key must be in what normal form? - - second normal form or higher Third Normal Form - - when all non-key columns depend on the key, the whole key, and nothing but the key Violation of Third Normal Form - - a non-key column depends on a column that is not unique Boyce-Codd Normal Form - - whenever column A depends on column B, then B is unique - same as Third Normal Form, except "non-key" is removed A table has: - columns A, B, C, D - candidate key (A, C, D) - primary key (A, C, D) - dependency D → B (in addition to dependencies on candidate keys) What is the normal form of the table? - - First Normal Form - the table has one candidate key, which is also a primary key
Dokument Information
- Hochgeladen auf
- 18. februar 2024
- Anzahl der Seiten
- 13
- geschrieben in
- 2023/2024
- Typ
- Prüfung
- Enthält
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