Normalization Quiz Tao Li Grant Horntvedt 1. Which of the following statements is true: a. Normal forms can be derived by inspecting the data in various tables b. Normal forms speed up all queries c. Normal forms reduce the risk of inconsistent update of replicated dataitems d. Normal forms completely eliminate all redundant storage of data-items Answer: C Normal forms of relational database theory give criteria for determining a table’s degree of immunity against logical inconsistencies and anomalies http://en.wikipedia.org/wiki/Database_normalizati on#Normal_forms 2. First normal form prohibits the occurrence of a. Null values in a column b. Repeating group in a table c. Multiple candidate keys in a table d. Multiple foreign keys in a table Answer : B Null values, multiple candidate keys, and multiple foreign keys are all allowed in first normal form. 1NF does prohibit repeating groups in a table. 3. If all non-keys in a table depend on the key, the whole key and nothing but the key, then the table is in a. 1NF, but not in 2NF b. 2NF, but not in 3NF c. 3NF d. BCNF Answer : C Requiring existence of “the key” ensures 1NF; requiring that non-key attributes be dependent on “the whole key” ensures 2NF; further requiring that non-key attributes be dependent on “nothing but the key” ensures 3NF. 4. When a part of a key determines a non-key, it is a violation of a. First Normal Form b. Second Normal Form c. BCNF d. All of the above Answer : B Requiring that non-key attributes be dependent on “the whole key” ensures 2NF. 5. Normal forms can be used with a. Relational data model b. Entity Relationship Model c. UML d. All of the above Answer : D Relational data models, Entity Relationship Models, and UML’s can all benefit from the use of normalization. 6. Can a software design tool identify functional dependencies? No. Functional dependencies are made during the process of developing the database. Design tools can only identify FD’s that do not exist.