#database
4 articles
01
·Databases·★ MEMBER·PAPER·10 min read
Distributed Databases — CAP, Replication and Consensus
The moment you add a second copy of your database, a brand-new question appears: which copy is right? Replication, quorums, CAP, two-phase commit, Raft and eventual consistency — from zero assumed knowledge down to the parameters you actually set in PostgreSQL and Cassandra.
02
·Databases·★ MEMBER·9 min read
Transactions and ACID — Concurrency Hell and the Isolation Levels
Why a balance never evaporates when the power dies mid-transfer, and why the bug that only shows up in production is almost always a concurrency bug. Atomicity, isolation levels, MVCC and deadlocks — from zero assumed knowledge down to the actual PostgreSQL and MySQL parameter names.
03
·Databases·FREE·10 min read
Database Internals — What Happens Behind a Single Line of SQL
Between hitting Enter on a SELECT and getting rows back, five stages run inside the database: parser, rewriter, planner, executor, storage. Here is why two plans returning identical rows can differ by orders of magnitude, and why stale statistics make a fast query go slow overnight — from zero background to the knobs you actually turn.
04
·Data Structures·★ MEMBER·10 min read
B-Trees and LSM-Trees — The Heart of Every Database
Almost every database ever shipped sits on a B-tree or an LSM-tree. Starting from one physical fact — storage can only be written a page at a time — here is why the two designs came out opposite, what write amplification really is, and how PostgreSQL and RocksDB differ, from zero background to the knobs you actually turn.