response database

(Cornor woods)Databases and database management systems (DBMS) work by centralizing data into a single repository such as a single database with multiple tables, each table representing a collection of attributes such as a table for customers and attributes such as name, phone, and email. “Management of data involves both defining structures for storage of information and providing mechanisms for the manipulation of Information (Silberschatz, Abraham, et al, 2003)”. Since databases can control the structure of data by managing the input and output, the data can be normalized and relationships to other related data can be maintained. Additionally, with the structured data provided by a database, data can be accessed more easily using easy to learn structured query language (SQL).

Once a database is defined with one or many tables, normalization can begin which is the process of normalizing data such as splitting compounded attributes into smaller attributes, such as splitting a name attribute into a first_name attribute and last_name into a last name attribute. Normalization involves the application of 3 primary rules, 1NF, 2NF, 3NF.

· (1NF): there should be no repeating groups and the and attributes should only contain one value (Kaula, 2015). An example violation of this rule would be an attribute such as “address” where the attribute contains the street address, city, state, and zip code. These values should instead be split out into their own attributes “city”, “state”, and “zip”.

· (2NF) “is that the key attributes determine all non-key attributes. A violation of second normal form occurs when there is a composite key, and part of the key determines some non-key attributes (Kaula, 2015)”. A volition of this rule would occur in the previous example, where name and city were a composite key, and there was a dependency on city, it would cause a violation of the second rule.

· (3NF) states that “non-key attributes should be independent (Kaula, 2015)”. That is to say that there are no dependencies on non-key fields such as the address attribute in the previous example. A violation of this rule would occur if a functional dependency existed on every candidate key (Chapple, 2019).

Database normalization directly impacts database design as it could impact the tables, relationships and overall data structure. When designing a database, best practice would be to develop a database diagram and perform normalization before creating the database.

 

Citations

Silberschatz, Abraham, et al. “Database Systems.” Encyclopedia of Information Systems, 2003, pp. 411–422.,  https://doi.org/10.1016/b0-12-227240-4/00028-9Links to an external site. .

Kaula, Rajeev. “Normalizing with Entity Relationship Diagramming.” TDAN.com, 1 Nov. 2015, https://tdan.com/normalizing-with-entity-relationship-diagramming/4583.

Chapple, Mike. “A Quick Guide to Understanding Database Dependencies.” Lifewire, Lifewire, 25 Oct. 2019, https://www.lifewire.com/database-dependencies-1019727.