CST334 - Week 3

Write what you learned this third week in CST 334 

Topic: Introduction to Memory Virtualization

This week, we read about how computer memory is virtualized and separated for each process. Virtualizing memory involves both the hardware and the operating system. Virtualization makes each program believe it has its own memory space. However, many programs often share memory at the same time, and the operating system manages these processes to ensure efficiency. The three main goals of memory virtualization are as follows:

1. Transparency – Implementing memory virtualization in a way that is invisible to the program.
2. Efficiency – Improving the management of memory to enhance the system's performance.
3. Protection – Ensuring that the operating system isolates processes from one another, so one process cannot affect the memory of other processes.

This week, we also worked more with C programming and piping in Linux for our lab. Essentially, piping allows one process to direct its output to the input of another process, enabling communication between them.

CST334 - Week 2

Write what you learned this second week in CST 334 

Topic: Processes

This week we had a lot of assigned reading and learned about processes, and how they interact with the CPU. A process is essentially a program in execution, actively using the CPU to perform tasks. The program itself remains inactive until it is run as a process. We also learned about voluntary and involuntary context switches. A voluntary context switch occurs when a process willingly yields the CPU to another process, often because it’s waiting for an event, such as reading data from a disk. In contrast, an involuntary context switch happens when the operating system forcefully removes a process from the CPU, typically to redistribute resources or because the process has exceeded its allotted time.

In addition, we completed our second lab, which involved programming in C and using the fork() call to create a child process by cloning the parent process. We also worked with other system calls, such as execlp(), to replace the process image and overwrite the current execution of the program with a new one.

CST334 - Week 1

Write a 1 - 2 paragraph description of what you learned this first week in CST 334

This was our first week of class, focusing primarily on an introduction to operating systems. We covered readings on operating systems and explored some basic computer architecture, among other topics. For our hands-on homework in Lab 1, we worked with the Linux command line and created a bash shell script. I completed my script using the vi editor, which was a bit confusing initially since I wasn’t familiar with the shortcuts and how to navigate. In addition to the lab, we had a short quiz on the reading and a discussion post to complete.

CST363 - Week 8

Briefly summarize the what you consider to be the three (3) most important things you learned in this course.

As I have stated in my prior journal entries, I did not have much knowledge regarding database design or databases in general, aside from my previous Java class where my team used SQLite for our Android movie app project. One of the most important things I learned was how to design a relational database schema using entity-relationship diagrams. Being able to visualize ER diagrams helped me understand the relationships between different entities in the database.

Secondly, I learned the fundamentals of SQL querying, particularly how to use commands like SELECT, INSERT, and DELETE (among others) to interact with and retrieve data from the database. This was my first experience with SQL commands, and I found the repeated homework assignments to be very helpful in solidifying my understanding of them.

Lastly, I enjoyed utilizing JDBC and MongoDB to work with a web application. We used Spring Boot to incorporate JDBC and MongoDB, and it was an overall enjoyable experience. It's one thing to interact with the database using SQL statements, but seeing the changes come to life while working hands-on with a web application was a rewarding experience.

CST363 - Week 7

Prompt for this week's journal entry. Compare MongoDB with MySQL.

What are some similarities?

On the surface, both MongoDB and MySQL are database management systems designed to store and retrieve data. Both systems utilize indexing and support various programming languages (such as Java, which we worked with for both systems throughout the semester).

What are some differences?

I would say the most noticeable difference is that, unlike MySQL, MongoDB does not require a predefined schema with tables, rows, and columns. Additionally, MongoDB uses its own query language, while MySQL uses Structured Query Language (SQL).

When would you choose one over the other?

You would want to use MySQL when handling structured data with many relationships between tables and involving complex transactions, such as in finance, where stricter data validation is necessary.

In contrast, you would opt for MongoDB when dealing with large amounts of unstructured or semi-structured data, especially if you frequently need to make changes to the schema and require scalability.

CST363 - Week 6

Summary of This Week's Learning

This week, our team created a web application in Java utilizing Spring and JDBC, which allowed us to work with the pharmacy database we designed last week. It was exciting to see the changes in the database, especially since we had mostly been working with SELECT statements in MySQL. Last semester, my team used an API for a movie database for our final project, but I had never worked with Spring before. In addition to this, we conducted peer reviews of our classmates' pharmacy database designs from last week, completed the short weekly quiz, and completed a MySQL homework assignment.

CST363 - Week 5

Include in your journal entry for this week the following

The web site "Use the Index Luke" has a page on "slow indexes". https://use-the-index-luke.com/sql/anatomy/slow-indexesLinks to an external site.

If indexes are supposed to speed up performance of query, what does the author mean by a slow index?


While indexes are generally used to speed up the performance of database queries, there are cases where they don't work as efficiently as expected. Markus Winand explains that a "slow index" occurs when the database has to follow a chain of leaf nodes continuously checking for matching entries, and also access the table. These steps may involve accessing many blocks, which can slow down the query rather than improve its performance.