Journal 18

 May 21 - May 27

Holy moly this course has flown by. I cannot believe we are already at the halfway point. I feel as though I have learned so very much in this short amount of time, and I am still rather enjoying the work in this course. I find that getting jUnit tests to pass in my Java code in this class is extra rewarding. To briefly summarize 5 things I have learned so far:

1. I can, at least somewhat, say I have learned to effectively use SQL. I came into this course not knowing anything at all about the language, so I feel as though I have learned and accomplished quite a bit in that aspect. I can use queries to create tables of various types, as well as insert and delete from them, among much more. 

2. I have learned about entity relationship diagrams (ERDs) and about their layouts and logical designs. Table diagrams, which are similar to ERDs, also contain entity relationships, but also utilize arrows between the columns to refer to keys within the tables. 

3. In the management of database systems, I have learned that tables must obey relational rules such as exactly one value per cell, no duplicate column names within the same table, no duplicate rows that have identical values in all columns, and the organization of rows does not affect query results (referred to as data independence).

4. I have come to learn about different possible data types within SQL, such as INT, SMALLINT, FLOAT, DECIMAL, CHAR, VARCHAR, DATE, TIME, DATETIME, TIMESTAMP, BLOB, BINARY, VARBINARY, IMAGE, POLYGON, POINT, and GEOMETRY. Although many of these have not been used in our labs and homework assignments, it was still very interesting to read about them in our textbook. It is neat to draw similarities between these variables and those used in Java programming. 

5. I have learned about aggregate functions such as COUNT, MIN, MAX, SUM, and AVG that process values from a set of rows and return a summery value. This has proven to be incredibly helpful in programming, and are great math shortcuts for what would otherwise be quite long and arduous tasks.

3 questions I still have regarding databases include:

1. How does database management and design play into data analytics for sports? Ex. baseball statistics across multiple seasons

2. At what point do large-scale companies need to update or upgrade their databases in order to maintain smooth functionality for customers? Ex. how many accounts can be made and stored before it begins to affect overall speed of functions

3. How big of a role does cybersecurity play in maintaining and protecting databases? Ex. how easy is it to hack in to steal information for those who understand database layouts and programming (don't worry FBI agent, I am not planning anything suspicious)