Database Design Essentials: ER Diagrams and SQL Mastery
ER Diagram Notations: Chen’s vs. Crow’s Foot
When designing an ER (Entity-Relationship) Diagram, there are two primary sets of symbolic notations: Chen’s Notation (traditional/academic) and Crow’s Foot Notation (modern/industry standard).
1. Chen’s Notation (Conceptual Focus)
Peter Chen’s original 1976 notation is highly detailed and uses distinct geometric shapes for every component. It is the gold standard for learning the theoretical foundations of databases.
Core Symbols in Chen’s Notation
- Rectangle:
MATLAB Basics: Environment, Commands, Plotting & Tips
🖥️ 1. MATLAB Basics & Environment
MATLAB = Matrix Laboratory — a numerical computing environment and programming language built for engineering and mathematical operations.
🔹 Interface Overview
| Area | Function |
|---|---|
| Command Window | Execute code directly. |
| Workspace | View and manage variables. |
| Current Folder | File directory for scripts. |
| Editor | Write .m scripts and functions. |
| Figure Window | Displays plots. |
| Help Browser | Documentation and examples. |
Prompt symbol: >>
Comment: %
Suppress output: ;
Continue line:
Bash Job Control, Linux Utilities and Example Scripts
Bash Job Control, Utilities and Example Scripts
The commands you listed are a mix of job-control utilities (fg, jobs, suspend) and standard Linux utilities (df, more).
Here is an explanation of the syntax and purpose for each:
1. Job Control Commands 🛠️
Job control commands are shell built-ins (mostly in Bash, KornShell, etc.) used to manage processes that are currently running in the background or suspended in the current terminal session.
(a) fg (Foreground)
- Syntax:
fg [%job_id] - Purpose: The
fgcommand
Operating System Exam Notes: Scheduling and Memory Management
Alright Buddy 👍
Here are 4–5 line, exam-ready answers for each topic you listed:
Operating System Concepts: Part 1
1. FCFS (First Come First Serve) Scheduling
FCFS is a non-preemptive CPU scheduling algorithm where processes are executed in the order of their arrival. The process that arrives first gets the CPU first. It is simple to implement using a queue. However, it can cause long waiting times and the convoy effect.
2. SJF (Shortest Job First) Scheduling
SJF selects the process with the shortest
Read MoreOperating System Structures and Core Components
1. Types of OS
Operating systems can be classified based on their structure, usage, and capability:
Batch Operating System
- Jobs with similar needs are grouped (batched) and run together.
- No direct interaction between the user and the computer during job execution.
- Goal: Maximize CPU utilization.
- Example: Used in environments that process large, repetitive tasks, like payroll systems.
Time-Sharing (Multitasking) OS
- The CPU switches rapidly between multiple jobs (processes) to give each user the impression
Mastering Modular Programming and Data Structures in C
Unit 4: Modular Programming Concepts
Modular programming is a software design technique that divides a program into smaller, independent, and reusable units called modules or functions. Each module performs a specific task, which helps in organizing, testing, and debugging programs more efficiently. By breaking a large problem into manageable pieces, programmers can focus on one module at a time, reducing complexity and improving readability. Modules can be developed, tested, and maintained separately,
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