Database Data Models: Structure, Keys, and ER Design
Data Models: Blueprint for Data Management
Data models serve as the blueprint for how data is structured, stored, and manipulated. The evolution of these models reflects the growing need for flexibility and the ability to handle complex relationships.
Evolution of Data Models
1. Hierarchical Data Model
The Hierarchical Model is the oldest of the three, popularized by IBM’s Information Management System (IMS) in the 1960s. It organizes data in a top-down, tree-like structure.
- Structure: Data is represented
Evolution of Computing: From Mainframes to Cloud Systems
Phases of Computing Evolution
Mainframe Architecture
Definition: Mainframe architecture is a centralized computing model where a large, powerful computer performs all processing, and users access it through dumb terminals.
Key Points:
- Expensive and large-scale systems
- Introduction of time-sharing
- Dumb terminals with no independent processing power
Client–Server Computing
Definition: Client–server computing is a model where client machines perform some processing while servers handle centralized services
Read MoreDatabase Management System Concepts and Architecture
1
What is DBMS? Describe the advantages and disadvantages of using DBMS
==ADatabase Management System (DBMS)
Is a software system that allows users to create, store, retrieve, update, and manage data in an organized way.
Examples: MySQL, Oracle, SQL Server, PostgreSQL.
Advantages of DBMS : *//Data Redundancy Control
DBMS reduces duplicate data by storing data centrally. *//Data Consistency
Since data is stored in one place, changes are reflected everywhere. *//Data Security
DBMS provides authentication,
Algorithmic Paradigms: Greedy, DP, and Backtracking
Greedy Approach
A Greedy Algorithm is a problem–
Solving strategy that makes the choice that looks best at the moment at each stage, hoping this local optimum will lead to a global optimum.
Key Characteristics
1.
Local Optimal Choice:
It focuses on making the locally best decision without considering the consequences for future steps.
2
No Reconsideration:
Once a choice is made, it is permanent and never revisited or revised (it is “short-sighted”).
3
Speed:
They are often simpler and faster to implement
Read MorePython Programming: OOP, RegEx, and Web Scraping
Practical 1: Car Class Implementation
Purpose: Demonstrate basic Object-Oriented Programming (OOP) by creating a Car class with accelerate and brake methods.
class Car:
def __init__(self, year, mpg, speed):
self.year = year
self.mpg = mpg
self.speed = speed
def accelerate(self):
self.speed += 10
print(f"The car speeds up. Current speed is {self.speed}")
def brake(self):
if self.speed >= 10:
self.speed -= 10
else:
Tampa Bay Rays Relocate to Abbotsford — White-Cats
Move the Tampa Bay Rays to Abbotsford!
The Fraser Valley White-Cats
I think the Tampa Bay Rays should move to Abbotsford because this city is growing, has many sports fans, and would support a Major League Baseball team.
If the team moves, they should be renamed the Fraser Valley White-Cats. The new name represents the animals and nature of British Columbia.
With a new stadium, new brand, and strong fan support, the Fraser Valley White-Cats would become very popular.
Reasons for the Move
- Abbotsford is