Attributes

Choosing the right tools for a database {1}

by Edwin T
The article i read goes over the basics of a database and what people need to know when considering implementing a database for their business.  The author talks about database design and management and also recommends software to make the process easier.  Under the “Databases Defined” section of the article, the author goes over the entities and attributes and how relationships can be established between entities in order to share data.  The products that the author recommends are FileMaker Pro 11.  With this anybody can create a database or ad-hoc report.  If the user is a bit more familiar with databases then the author discusses Microsoft Access 2010 and Alpha Five v10 Developer to create highly customized solutions using the databases as back-ends. read more...

The Purpose of Primary Keys {4}

by Jasmine C
The article I read discussed primary keys.  The article states that primary keys are derived from candidate keys.  The focus of this key is to uniquely identify a row in a table.  As a rule of thumb, a candidate key should “contain the fewest number of attributes possible to identify rows individually and uniquely” (Schraml).  If a table does contain any composite keys then a surrogate key is created.  The purpose of this key it to basically create a data item that would not exist.  A problem that was stated in the article is that many people confuse the concept that a primary key is a logical and not a physical concept. When designers implement the physical aspect, an example of a mistake would be that they add extra columns onto the primary key. As a result, the logical primary key no longer exists which can eventually lead to your database system not operating properly. read more...

Conceptually understanding data models {2}

by Jasmine C
In summary, the article I read reiterates the importance of having a well designed data model.  Without a good data model, then the information in the database based on that model is not going to correspond.  The data model is going to contain the information about the “entities , their associations and attributes within the intended business” (Huang).  As we all know, if the data model is messed-up, the the database that it is based off is not going to have a correct representation of reality.  Something that many people need to understand is that conceptually, data modeling is very easy to mess up.  This is true especially for student database designers.  Cognitively speaking, student designers do not yet contain the ability to effectively understand the reasoning behind data modeling techniques.  Domain knowledge and cognitive fit are two variables that student designers need to understand in order for them to progress to expert designers.  These two variables are essential for conceptual data modeling. read more...