06 – Database Internals
This is where you learn what’s happening under the hood.
📌 Overview
- Understand how storage, indexing, logging, and coordination work internally
- Build mental models that make performance tuning intuitive
🧠 Core Internal Topics
[[B-Tree vs LSM]]
- Compare write/read patterns of B-Tree and LSM
- Understand compaction, write amplification, and read amplification
[[Buffer Pools]]
- Learn how in-memory pages cache disk blocks
- Understand eviction policies (LRU, clock, etc.)
[[WAL Internals]]
- See how logs ensure durability and crash recovery
[[Query Planner]]
- Understand how logical queries become physical execution plans
- Learn about join strategies, scan types, and cost models
[[MVCC Internals]]
- Dive deeper into snapshots, versions, and garbage collection
[[Raft Consensus]]
- Understand key ideas of log replication and leader election
[[Paxos]]
- Learn the theory behind consensus in distributed systems
[[2PC & 3PC]]
- Understand distributed transactions and commit protocols
[[Hashing & Bloom Filters]]
- Learn how probabilistic data structures speed up lookups and joins
🔗 Connections
- Deepens concepts from [[01 - Fundamentals]] and [[02 - RDBMS]]
- Provides the foundation for [[08 - Modern Databases]] designs