iRobot90/pesadb-edge-rdbms

Lightweight, offline-first embedded SQL database for African edge payments. Built for Pesapal Junior Dev Challenge '26. Features hash indexing, type-safe schema enforcement, and a merchant transaction dashboard. # PesaTrack & PesaDB > **Pesapal Junior Dev Challenge '26 Submission** **PesaTrack** is a Merchant Transaction Dashboard powered by **PesaDB**, a custom-built, lightweight, embedded Relational Database Management System (RDBMS) designed for offline-first payment systems in African markets. --- ## Table of Contents * The Vision * Quick Start * Features * Architecture * Performance * Usage Examples * Testing * Project Structure --- ## The Vision: "Payments at the Edge" In many African markets, internet connectivity can be intermittent. Relying on cloud-only databases for Point-of-Sale (POS) systems can lead to lost transactions. **PesaDB** is designed as an **embedded, offline-first SQL engine** that runs locally on the merchant's device, ensuring: 1. **Zero Latency**: Transactions are recorded instantly in-memory 2. **Data Integrity**: Type-safe schema enforcement prevents bad data entry 3. **Persistence**: Data is flushed to disk (`pesadb.json`) for durability 4. **Simplicity**: A lightweight REPL and SQL interface for easy debugging --- ## Quick Start ### Prerequisites - Node.js (v16+) ### Installation & Setup ```bash # Install dependencies npm install # Seed the database with sample data npx ts-node seed.ts # Option 1: Run the REPL (Interactive SQL Mode) npx ts-node src/repl/index.ts # Option 2: Run the Web Dashboard npx ts-node src/server/index.ts # Then open localhost in your browser ``` ### Test the Database ```bash # Run basic database tests npx ts-node test_db.ts # Test enhanced JOIN operations npx ts-node test_enhanced_join.ts # Test B-Tree indexing npx ts-node test_btree.ts ``` --- ## Features ### Core Database Features #### 1. **Relational Database Management System** - Custom SQL engine with typed columns (`string`, `number`, `boolean`) - Primary keys and unique constraints - Full CRUD operations (CREATE, INSERT, SELECT, UPDATE, DELETE) - Type enforcement and validation - Data persistence to JSON #### 2. **Advanced J …