Developer builds SaarDB from scratch in Go, starting with a Write-Ahead Log

SaarDB is an open-source learning project aimed at building a relational database from first principles using Go, one layer at a time. The project begins not with SQL parsing but with a simple key-value store, which the author argues can be extended to support full relational database functionality. The first major challenge tackled is durability — ensuring that data survives process crashes — by writing changes to disk before updating the in-memory store. This disk-first approach, known as a Write-Ahead Log (WAL), eliminates a dangerous window where memory and disk can fall out of sync. The series prioritizes understanding database internals and tradeoffs over building a production-ready system.