Skip to main content

CST 363 Week 3 Learning Journal

 

  1. Someone described normalization rule as  "a non-key column depends on the key, the whole key, and nothing but the key, so help me Codd."  Key refers a primary or other candidate key of a table.  If the key has multiple columns, then "whole key" means  all columns together and not just some part of the key.  Explain in your words what 3rd normal form is and why it is important.
  2. What is an SQL view.  How is it similar to a table? In what ways is it different?

1. From the research I conducted online, 3rd normal form is where a table is organized in such a way that there are no transitive relationships in this system. This means that the key and associated values of a table are directly related. For example, if you have a table with a course id (primary key), course title, instructor and salary in a table, the instructor and salary columns can be moved into a separate table because the instructor and salary are not dependent on the course id and title.

2. SQL views are a way of modifying an existing table to present the data in a way that may make more sense to the user. One of the best uses for a view is to allow users access to certain parts of the table. This could be for security reasons. A table could contain the social security numbers and salaries of employees. The table may also contain information that employees need but the SSN and salaries should be kept hidden. Using a view the same table could be used but the SSN and salaries left hidden. This allows the original table to maintain it's current form and still allow users to access the table via the protected view.

Comments

Post a Comment

Popular posts from this blog

CST311 Week 6 Journal

 This week, we developed a deeper understanding of the network control plane and explored routing algorithms such as Dijkstra and Bellman-Ford, focusing on how they determine the most efficient paths for data transfer. We also learned about the SDN control plane, which allows for dynamic network management and routing. In addition to the theory learned this week, we conducted a network lab exploring the use of a basic SDN controller using Mininet and Wireshark. We looked at how Internet Control Message Protocol (ICMP), can be used for network diagnostics, particularly for network troubleshooting with tools like ping and traceroute.
Post a Comment
Read more

CST335 Week 7 Journal Entry

 This week I learned about input/output (I/O) devices and their interactions with the operating system (OS). Two types of devices I learned about were block and character devices. Block devices, like hard drives and SSDs, store data in fixed-size blocks and allow random access, making them ideal for large data transfers. Character devices, such as keyboards and mice, handle data streams one character at a time, supporting sequential access. The OS play a crucial role in managing these devices through device drivers that provide a standard interface to interact with the hardware. Performance characteristics of hard drives, such as seek time, rotational latency, and transfer rates, are pivotal in determining overall system efficiency. By calculating transfer rates for different workloads, I learned how disk access patterns significantly impact performance. Additionally, understanding RAID levels provided insights into how redundancy and striping enhance data reliability and performan...
Post a Comment
Read more

Leetcode Practice Reflection 1.Two Sum

LeetCode Practice Reflection - 1. Two Sum Date:   19MAY25 What I Worked on Today: Practiced doing LeetCode Problem 1.Two Sum. What I Learned: - How to use the enumerate() function - How to optimize possible solutions after considering brute force methods - How to declare a new dictionary (key value pair) Code Snippet I Wrote or Studied: class Solution(object): def twoSum(self, nums, target): seen = {} for i, num in enumerate(nums): compliement = target - num if compliment in seen: return [seen[compliment], i] seen[num] = i In My Own Words: This function takes in a list of numbers and will return the index of the two numbers that add up to the provided target value. The way this program works is that it creates a dictionary called "seen". It will then iterate through the list of numbers and use the enumerate function to keep track of the index and the value of the specific item in the provided list. The for loop will calculate the compliment numbe...
Post a Comment
Read more