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What Is ETL? Every dashboard you have ever trusted, every report your manager pulled up in a meeting, and every recommendation Netflix or Amazon has ever shown you — all of it depended on a quiet, unglamorous process running in the background called ETL. This guide explains exactly what that…
What Is Database Read / Write Splitting Used For? A beginner-to-production walkthrough of one of the simplest and most powerful tricks for scaling relational databases — explained with real-life analogies, Java code, and diagrams from Netflix-scale systems down to your first side project. 01 · Intro & History02 · Problem03…
What Is a Deadlock in Databases? A complete, beginner-friendly guide to why deadlocks happen, how databases detect and resolve them, and how to design applications that avoid them — with real diagrams, real Java code, and real production lessons from banking, e-commerce, ticketing, ride-sharing, and streaming systems. 01 · Intro…
What Happens When You Add Too Many Database Indexes? Indexes make reading data fast. But every index you add is a promise your database has to keep forever — on every single write. This tutorial explains, from first principles, exactly what that promise costs, why teams accidentally end up with…
Schema-on-Read vs Schema-on-Write Two different philosophies about one simple question: when should a computer decide what your data means? Answer that question well, and you can design databases, data lakes, and APIs that scale for years. Answer it badly, and you get slow queries, broken reports, or a swamp of…
A beginner-friendly, complete guide to relational vs NoSQL databases: what each one really is, how they store and scale data, the CAP theorem, ACID vs BASE, real-world architectures, and a practical decision checklist for picking the right database for your system.
What Is a Database Read Replica? A complete, beginner-friendly guide to one of the most important scaling patterns in modern software systems — explained from first principles, with real production examples from companies like Netflix, Amazon, and Uber. 01 · Introduction02 · The Problem03 · Core Concepts04 · Architecture05 ·…
A full-length guide to the primary key — history, B-tree internals, natural vs surrogate keys, composite keys, sharding, distributed IDs, security, caching, APIs, Java examples, and real-world lessons from Netflix, Amazon, Uber, Instagram, and Google.
A complete, beginner-friendly, production-grade guide to database connection pooling: why opening a fresh database connection for every request is one of the most expensive mistakes in software engineering, and how connection pools quietly fix it inside almost every production system. Covers the full origin story from the 1990s Object Pool…
A complete, beginner-friendly, production-grade tutorial on polyglot persistence: why modern architects deliberately use many different databases in one system, when it is worth the added operational cost, and how it actually works. Covers the full history from Edgar Codd’s 1970s relational model through the NoSQL movement and the 2011 naming…