Data Structuring, Acquisition, Cleaning, and ETL Cheatsheet
Module 1 Cheatsheet — Foundations, Acquisition, DOM/XPath, Structuring
1) What “Big Data” means:
No single size cutoff. Think:
Volume (lots of rows/large objects), Variety (heterogeneous), Velocity (fast-changing), Veracity (quality).Implication: choose tools/storage/pipelines that match data scale and shape.
2) Three canonical encodings:
Tables / Relations / DataFrames
Heterogeneous columns; ideal for SQL/Pandas joins, filters, aggregations.
Arrays / Matrices / Tensors
Uniform numeric cells;
Read MoreCritical Perspectives on Black Diaspora Identity and Struggle
I. Maafa: The Scope of the Transatlantic Slave Trade
Gomez, Exchanging Our Country Marks, Chapter 1: “Time and Space”
Summary: Gomez explores how African identities were preserved, adapted, or transformed in the Americas. He challenges the idea that Africans lost their cultural roots during enslavement and instead argues that memory, kinship, and religion helped sustain African identities.
Key Concepts:
- Maafa: A Kiswahili term meaning “great disaster,” used to describe the transatlantic slave trade
Philosophical Reflections on Power, Happiness, and Society
Philosophical Reflections on Personal Motivation
Hobbes, Power, and the Pursuit of Happiness
Since I was a kid, my parents didn’t pay much attention to how I was doing things in general; they were more focused on my older brother. While studying in school, I understood that happiness was all I was looking for, and all my actions caused and helped decide my purposes in life. Aristotle discusses the importance of virtue and happiness through daily life, but also conducting yourself in a way that accustoms
Read MoreAncient Literary Traditions from Around the World
Understanding Myths in Literature
The word ‘myth’ often refers to a person or event that stands out for a particular reason, becoming an object of admiration and a model for others. Key features of myths include:
- The narration of an event prior to historical time.
- The involvement of superhuman beings.
- Attempts to explain the fundamental issues of existence.
- Holding religious significance.
Types of myths include cosmological myths and those detailing the practices of worship of gods and heroes.
Ancient
Read MoreSpanish Post-War Literature: Novel and Theater in the 1940s
The Cultural Impact of the Spanish Civil War
The dramatic consequences of the Civil War were felt not only in the social, political, economic, and human spheres, but also, and very intensely, in the field of culture. With the end of the war, the best writers went into exile, mainly to Latin America, but they kept in touch with the writers who remained in Spain, and their books circulated widely, despite censorship.
Spanish Novel of the 1940s: Social Realism and Exile
The social theme is present throughout
Read MoreMastering SQL: Practical Database Design and Query Examples
SQL Database Management: Supplier and Product Inventory
Defining the Inventory Schema (DDL)
We begin by setting up the database structure for tracking suppliers and their products. Note the use of PRIMARY KEY, FOREIGN KEY, and CHECK constraints for ensuring data integrity.
Supplier Table Creation
CREATE TABLE Supplier (
SupplierID INT PRIMARY KEY,
Name VARCHAR(100) NOT NULL,
City VARCHAR(50)
);Product Table Creation
CREATE TABLE Product (
ProductID INT PRIMARY KEY,
Name VARCHAR(100)Fundamentals of Software Development, Testing, and Modeling
What is Software and Its Common Myths?
Definition of Software
Software is a set of instructions, data, or programs used to operate computers and execute specific tasks. It is the intangible component of computers, as opposed to hardware.
Types of Software
- System Software: e.g., Operating Systems
- Application Software: e.g., MS Word, Web Browsers
- Programming Software: e.g., Compilers, Editors
Common Software Myths
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Core Software Engineering Concepts
Software Engineering
Read MoreEconometric Methods for Establishing Causality
1. RCTs Versus Quasi-Experimental Methods
A randomized controlled trial bakes causality into the data: random assignment severs every systematic link between treatment status and unobserved factors. Consequently, the simple difference in average outcomes is unbiased, provided compliance and sample integrity hold. The four quasi-experimental tools imitate this causal magic only by leaning on single-point assumptions:
- Ordinary Least Squares (OLS): Assumes no omitted variable is correlated with the regressor.
Software Maintenance, Evolution, and Documentation Best Practices
Software Maintenance Fundamentals (Week 1)
Definition of Software Maintenance (SM)
- “The modification to a software product after delivery to correct faults.”
Maintenance vs. Software Evolution
| Maintenance | Evolution |
|---|---|
| All activities preventing failure or decay of a software system. | Activities that provide new or changed functionality only. |
Software Aging and Decay
- Software ages when it does not adapt to changing technology, user needs, or competitors.
Lehman’s Laws of Software Evolution
- Continuing Change:
- Real-
Aggregate Supply, Demand, and Economic Growth Factors
Aggregate Supply and Demand Dynamics
Short-Run and Long-Run Aggregate Supply
Determinants of Short-Run Aggregate Supply (SRAS)
What are the determinants of short-run aggregate supply? Changes in input prices, taxes, and business and inflationary expectations.
Determinant of Aggregate Supply (AS)
What is a key determinant of aggregate supply? Productivity.
SRAS Curve Slope
The short-run aggregate supply curve slopes upward because profits increase at high price levels and because many input prices are slow