4NF – Fourth Normal Form — Learn free

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Questions 1–10 of 10

1. What kind of dependency does Fourth Normal Form (4NF) address?
Question 1A. Multi-valued dependenciesB. Partial dependenciesC. Transitive dependenciesD. Join dependenciesE. Domain constraints
2. Which conditions must a table meet to be in Fourth Normal Form?
Question 2A. It is in 1NF and has no repeating groupsB. It is in BCNF and does not contain two or more independent multi-valued facts about the same keyC. It is in 3NF and every determinant is a superkeyD. It is in 5NF and every fact has explicit time validityE. It is in 2NF and has a single-column primary key
3. What is a multi-valued dependency?
Question 3A. A non-key attribute that depends on another non-key attributeB. A column that stores several values separated by commasC. One key determining multiple independent sets of values that are unrelated to each otherD. A composite key with more than two columnsE. A foreign key that points to two different tables
4. What is the "Cartesian explosion" described in relation to Fourth Normal Form?
Question 4A. The growth of a table when repeating groups are split into rowsB. The duplication of loan amounts across repayment rowsC. The rapid increase in table count after 6NF decompositionD. The creation of false combinations when independent lists are stored in the same tableE. The failure of a join to reconstruct the original table
5. In the loan example, a loan has two collateral types and two guarantors stored in one table. How many rows does the table produce?
Question 5A. OneB. TwoC. ThreeD. EightE. Four
6. How is the loan collateral and guarantor problem resolved under Fourth Normal Form?
Question 6A. By creating LoanCollateral (LoanID, CollateralType) and LoanGuarantor (LoanID, GuarantorID) as separate tablesB. By storing collateral types and guarantors as comma-separated listsC. By adding a surrogate key to the combined tableD. By moving both lists into the Customer tableE. By making CollateralType part of the primary key of the Loan table
7. How does Fourth Normal Form differ in focus from the earlier normal forms?
Question 7A. It focuses on atomic values rather than keysB. It focuses on how independent lists behave when stored together rather than on how attributes depend on keysC. It focuses on time validity of each attributeD. It focuses on domain and key constraints onlyE. It focuses on analytical query performance
8. In which kinds of domains is a failure to recognise multi-valued dependencies most likely to cause subtle data distortions?
Question 8A. Domains with a single flat tableB. Domains with only one-to-one relationshipsC. Domains involving multiple independent classifications, tags, roles or attributesD. Domains with no composite keysE. Domains that use only surrogate keys
9. Which of the following is NOT stated as something Fourth Normal Form provides?
Question 9A. Protection against structural inflationB. Protection against logical inaccuracies caused by storing independent facts togetherC. Assurance that each table represents one coherent type of relationshipD. Elimination of redundancy that appears only when projections are re-joinedE. Avoidance of unintended combinations
10. Why do many real-world systems implicitly satisfy Fourth Normal Form?
Question 10A. Because databases enforce 4NF automaticallyB. Because most systems never use composite keysC. Because multi-valued attributes are forbidden in 1NFD. Because 4NF is only relevant to data warehousesE. Because designers instinctively separate independent relationships