Blog Post 5 - Hovey

Relational Database Theory

What is a Relational Database? 

    Relational Database theory is typically a topic a lot of engineers that don’t create databases as part of their jobs usually avoid learning due to the dry treatment that is given to it by most authors or teachers/peers. A relational database is one whose symbols or characters are organized into a collection where they are categorized by different relations. As discussed in class, the language SQL (Structured Query Language) uses relational databases in the context of theory because it is convenient to stick with idea of ‘relations’ instead of tables. Figure 1  shows an example of how information or ‘relations’ are used to quickly pull information from a much larger spreadsheet. In example, if the table had over 1,000 patient Id’s a relational database would allow a user to pull up all the desired information for a desired patient.(3)  

Figure 1

Creating a Relational Database Design

    The reason why databases are created is to take some system in the real world and be able to model it using technology. Some benefits that database’s bring to models include:

• Real time data entry
• Increased in efficiency for data retrieval and reporting
• Specific changes to the schemes of databases are easy to track and make

    There are three separate relationships that can be made: a one-to-one, one-to-many, or a many-to-many relationship. These are pretty self explanatory, in example a one-to-many relationship sets one parameter to reference many different elements inside a worksheet. The same idea works for the other two relationship as well. These different parameters are then put together to create a databases that reacts to whatever the user needs to help provide precise information. The different concepts of each relationship are explained as shown in Figure 2.(2)

Figure 2

What are some issues in relational databases?

    There were two issues that were highlighted during Paris C. Kanellakis’s Elements of Relational Database Theory and those were incomplete information and database updates. Incomplete information is exactly what it sounds, there is insufficient algebraic mechanisms or symbols included that are being referenced that would create null values. To help solve this issue, there have been proposed modeling tools for uncertainty, however their applicability is hard to assess and can create complexity issues inside the database. Ultimately, there are a lot of ‘fixes’ or partial answers, but no satisfactory full solution yet that will fix this issue.(1)

The next issue that comes up on a regular basis are database updates. This problem refers to the manipulation of languages while updating relations in regards to the characteristic that  distinguishes database updating from updating the state of a database. To put this into simpler terms, if a database goes through an update whether it's by a user or an automated program, the specific relations may be altered or the database itself may be updated thus creating possible issues with not carrying over certain information to the newer model.(1)

Comparing with a regular database

    The definition according to Hugh Darwen explains a database as an organized collection of data that is machine-updatable and typically available to a community of users, with the ability to vary requirements. Different databases will be created depending on the suitability or extent of requirements set out by the user(s). The big separation between regular databases and relational databases is in the name, the relations. Databases will only deal with one-to-one as every symbol will have a married symbol until a different relation is introduced into the system. This difference can be viewed by analyzing figure 2.(3) 

Work Cited

1. Kanellakis, Paris C. "Relational Database Research" Relational Databases. N.p., n.d. Web. 09 Feb. 2017.
2. Litwin, Paul. "Fundamentals of Relational Databases." Fundamentals of Relational Databases. N.p., n.d. Web.  
3. Darwen, Hugh. An Introduction to Relational Database Theory. Place of Publication Not Identified: Ventus, 2009. An Introduction to Relational Database Theory. Web.
   
   
   Peer Comments:
   
   Maria R - Before this class as well as reading your post, I had no knowledge of how SQL was used or why it was important. When you related it to Oracle and Microsoft Access I was able to gain a grasp of the concept since I have some basic knowledge of each of those programs. I was able to understand the process of SQL from the Microsoft example you wrote out, as that was extremely descriptive and gave us a step by step analysis. I agree with you that SQL is very important to creating a successful and efficient database however I find it extremely boring to do as my mind doesn't particularly think in code, as I prefer visuals.
   
   Maissoun K - I as well did relational databases and I found out reading a different view of the same topic from a peer was extremely helpful for me to better understand the concept. learning about the differences between hierarchical models and network model as well as how they affect databases. I didn't focus on the research on actually writing the code out so seeing how people accomplish these tasks inside a script was extremely helpful for me! Also, learning about how there are different languages for larger or smaller servers.
   
   Hayley S - I know we have spoken about how databases have affected the construction industry in class, but learning more about it in terms of researched and productivity usage was interesting to read about. I wrote a little on the legal issue that companies could run into with BIM because is the model intellectual property of the design firm or does that come with the package when a client brings on the firm to design their project? It's interesting to see how you described the issue as it falls on the design firm legally however protects a specific engineer who directly worked on the documents.