🔧 Dissecting PostgreSQL — Why Being Read-Optimized Comes at the Cost of Write Speed

You've probably heard this before — "Postgres is great but not ideal for write-heavy workloads."

But why? What is actually happening under the hood that makes writes slow? And how is Cassandra or any LSM-tree database fundamentally different?

This post is a deep dive into Postgres internals — storage layout, MVCC, WAL, B-Tree indexes, and how...