WAL on S3 — Why Object Storage Simplifies Database Design
· 3 min read
WAL on S3: What You Get for Free
When you build a database on local disk, the WAL (Write-Ahead Log) carries a heavy burden. It must guarantee that committed transactions survive crashes — every write hits the WAL before it touches data files. If the machine loses power mid-write, the WAL is your only path back to a consistent state.
Two hard problems come with building a WAL on local disk: