COMPUTER SCIENCE AND ENGINEERING
SQL
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Records do not depend on anything other than the table’s PK
|
|
|
The PK is not added
|
|
|
The FKs are limited to one only
|
|
|
The tables all relate to one another
|
Detailed explanation-1: -The third normal form requires that all columns in a relational table are dependent only upon the primary key. A more formal definition is: A relational table is in third normal form (3NF) if it is already in 2NF and every non-key column is non transitively dependent upon its primary key.
Detailed explanation-2: -Third normal form (3NF) is a database schema design approach for relational databases which uses normalizing principles to reduce the duplication of data, avoid data anomalies, ensure referential integrity, and simplify data management.
Detailed explanation-3: -To normalize a table from 1NF to 3NF, you need to normalize it to 2NF first then to 3NF. In the normalization process, you decompose a table into multiple tables that contain the same information as the original table. The normalization process usually removes many problems related to data modification.
Detailed explanation-4: -A properly normalised design allows you to: Use storage space efficiently. Eliminate redundant data. Reduce or eliminate inconsistent data.