Week 4 Reading Notes

Notes and thoughts on the Wikipedia database article 

“Outside the world of professional information technology, the term database is sometimes used casually to refer to any collection of data (perhaps a spreadsheet, maybe even a card index).”

- This is just what I was thinking as I began reading this article! I think the word “database” is overused and often construed to represent a spreadsheet. I have a better idea what it means now that I’m an LIS graduate student, but prior to this experience I thought a database was any kind of chart/spreadsheet - like an Excel spreadsheet, for instance. 

- Databases are “organized to model relevant aspects of reality in a way that supports processes requiring this information”.

“Well-known DBMSs include MySQL, PostgreSQL, SQLite, Microsoft SQL Server, Microsoft Access, Oracle, SAP, dBASE, FoxPro, IBM DB2, LibreOffice Base and FileMaker Pro.”

- The only ones I’ve ever heard of are SQL and Microsoft Access! Wow, I have a lot to learn. I wonder what the Mac DBMS is and if I already have it on my computer.

“A cloud database relies on cloud technology. Both the database and most of its DBMS reside remotely, "in the cloud," while its applications are both developed by programmers and later maintained and utilized by (application's) end-users through a web browser and Open APIs.”

- It looks like the trend toward cloud-based computing is also applicable to databases and DBMSs.

“One way to classify databases involves the type of their contents, for example: bibliographic, document-text, statistical, or multimedia objects. Another way is by their application area, for example: accounting, music compositions, movies, banking, manufacturing, or insurance. A third way is by some technical aspect, such as the database structure or interface type.”

- I didn’t know there were so many database types! I'm also guessing that ibliographic databases are prolific in libraries. 

“Hypertext databases are particularly useful for organizing large amounts of disparate information. For example, they are useful for organizing online encyclopedias, where users can conveniently jump around the text. The World Wide Web is thus a large distributed hypertext database.”

- I think this is a really interesting way to think about the internet. It makes me view it in a slightly different light. Before this class, I never really thought about the infrastructure of the internet.

“It also contains all the information needed (e.g., metadata, "data about the data", and internal data structures) to reconstruct the conceptual level and external level from the internal level when needed.”

- I’ve been hearing the word “metadata” a lot since I entered the LIS program so I’m interested to learn more about it.

Notes and thoughts on the entity–relationship model

“In software engineering, an entity–relationship model (ER model) is a data model for describing a database in an abstract way.”

- I’m starting to feel overwhelmed with this information. I can’t visualize the way a database is managed/operated only through reading articles. 

"The three models: Conceptual Database, Logical Database, Physical."

- Is one of these the predominant model for public library data storage?

Notes and thoughts on the database normalization process article

“Things to memorize before normalizing:

1. No repeating elements or groups of elements

2. No partial dependencies on a concatenated key

3. No dependencies on non-key attributes”

- I think the normalization process of putting data into a true database (and not just an Excel spreadsheet) allows us to find the answers to more complicated questions regarding the relationships within the data set.

“rows/columns are the same as tuples/attributes”

- This terminology is already a little confusing to me! I’m glad the author of this article is breaking it down into simpler language.

“Our database schema now satisfies the two requirements of First Normal Form: atomicity and uniqueness. Thus it fulfills the most basic criterion of a relational database.”

- The articles from this week were a little difficult for me to visualize and understand so I watched some YouTube videos for more visual examples. I’m also looking forward to discussing this in class on September 23rd.