Denormalization is the process of attempting to optimize the read performance of a database by adding redundant data or by grouping data
First Normal Form means a form with a primary key, no row-ordering or column ordering as an intrinsic and meaningful aspect of the view and no nullable fields
1NF table is in Second Normal Form if and only if all its non-prime attributes are functionally dependent on the whole of a candidate key. Non-prime attributes do not form part to any candidate key. When 1NF table has no composite candidate keys it automatically becomes 2NF.
Anomalies: Updation has occurred in linked table but foreign key in linking table has not been updated. This creates updation and insertion anomaly. Deletion has occurred in linked table but foreign key in linking table has not been deleted. This creates deletion anomaly.
- IT Notes
- Data Model
- Logical Data Model
- Physical and Relational Data Model
- Data Normalization
- Managing the RDBMS
- Performance Issue
- MS SQL
- URL Rewrite
- Project Management