Final answer:
The 3rd normal form (3NF) and Boyce-Codd normal form (BCNF) are both used in database normalization to eliminate redundancy and ensure data integrity.
Step-by-step explanation:
The 3rd normal form (3NF) and Boyce-Codd normal form (BCNF) are both used in database normalization to eliminate redundancy and ensure data integrity. While the two forms have similarities, the main difference lies in the dependency preservation rule. In 3NF, a table must be in 2NF and remove any transitive dependencies, while in BCNF, a table must be in 3NF and eliminate all non-trivial determinants.
For example:
- In 3NF, if we have a table with columns for customer ID, customer name, and customer address, it would be necessary to remove the customer address column as it depends on the customer ID.
- In BCNF, after removing the customer address column, if we find that the customer name now depends on both customer ID and another attribute such as customer phone number, we would need to further modify the table to satisfy BCNF.