📦 Data Warehouse Project

This data warehouse project demonstrate my skills in ETL, data modeling, and analytics using SQL Server, following industry best practices.

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🏗️ Data Architecture

This project uses the Medallion Architecture with three layers to progressively refine and structure data:

• 🔸 Bronze Layer: Raw data ingested directly from CSV files into staging tables to preserve original format.

• 🔹 Silver Layer: Cleaned, standardized, and normalized data to make it analysis-ready.

• 🏅 Gold Layer: Final transformation into a star schema with fact and dimension tables optimized for BI and reporting.

  

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📖 Project Overview

This project covers:

1. Data Architecture – Building a scalable modern warehouse using Medallion architecture.
2. ETL Pipelines – Extracting, transforming, and loading structured data into SQL Server.
3. Data Modeling – Designing star schemas for efficient querying and business insights.

🧠 Key Skills Demonstrated

• SQL Development
• Data Engineering & Pipelines
• Data Cleaning & Integration
• Dimensional Modeling
• Analytical Thinking

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📋 Specifications

• Data Sources: Two CSV files representing ERP and CRM systems.
• Data Quality: Cleaned missing values, handled duplicates, and resolved inconsistencies.
• Data Integration: Unified ERP and CRM data into a single, analytics-friendly model.
• Scope: Focused on recent transactional data; no SCD or historization implemented.

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📂 Repository Structure

data-warehouse-project/
│
├── project_data/               # Raw datasets (ERP and CRM)
│
├── documents/                  # Architecture docs and diagrams
│   ├── data_catalog.md
│   ├── data_flow.drawio
│   ├── data_models.drawio
│
├── scripts/                    # SQL scripts organized by layers
│   ├── bronze/
│   ├── silver/
│   ├── gold/
│
├── quality_checks/            # Data validation and quality test files
│
├── README.md                  # Project overview and instructions
├── LICENSE                    # License info

🛡️ License

This project is licensed under the MIT License.

Author: Peter Opapa © 2025