Learning track · 18 concepts

Databases & Storage

Storage foundations for Turbopuffer-class systems: B-trees, LSM trees, WAL, compaction, partitioning, replication, object storage.

What mastery looks like

This track contains 18 connected concepts rather than an unordered reading list. Mastery means you can move from vocabulary to mechanisms, predict how the system behaves under pressure, and support a design decision with code, measurements, or a failure-recovery exercise. For Databases & Storage, use the track description as the boundary: learn enough detail to reason clearly about storage foundations for turbopuffer-class systems: b-trees, lsm trees, wal, compaction, partitioning, replication, object storage.

A useful explanation names the state involved, the operation that changes it, the resource or safety constraint, and the observable signal that tells you whether the mechanism works. Avoid stopping at product names. Compare at least two approaches, state what each optimizes, and identify what breaks first as scale, concurrency, latency, or uncertainty increases.

Suggested study sequence

Start with the core concepts at the top of the list and write a one-paragraph mechanism note for each. Continue through the core concepts by alternating explanation with an executable drill. Treat LSM Tree, Compaction, Columnar Storage, Storage Engines as integration work: they should combine earlier mechanisms rather than introduce disconnected facts.

At the end of each session, record one decision you can now make, one failure mode you can now predict, and one unanswered question. Revisit that question through the linked primary sources, then prove the answer in the Playground or a real repository. The track is complete when you can transfer the reasoning to an unfamiliar system, not when every page has been opened.

Roadmaps

Concepts in this track

core

B-Tree

The balanced, disk-friendly tree behind most relational indexes.

advanced

LSM Tree

Log-structured merge tree: write-optimized storage via sorted runs.

core

Write-Ahead Log

Append-only durability log written before the data pages.

advanced

Compaction

Merging sorted runs to reclaim space and bound read amplification.

core

Object Storage

S3-style blob storage: cheap, durable, high-latency, immutable objects.

advanced

Columnar Storage

Column-oriented layout for analytics: compression and vectorized scans.

core

Secondary Indexes

Extra indexes for non-primary-key lookups, and what they cost on writes.

advanced

Sharding

Range/hash/geo partitioning.

advanced

Replication

Leader-follower, multi-leader, quorum.

core

Transaction Processing

ACID, MVCC, isolation anomalies, locking, optimistic control, serializability, commit, and recovery.

core

Data Warehouses & Lakehouses

Columnar files, table formats, storage-compute separation, batch execution, metadata, governance, and lakehouse architecture.

core

Isolation Levels & MVCC

What each isolation level actually prevents, and how MVCC delivers snapshots without read locks.

core

Join Algorithms

Nested-loop, hash, and merge joins — and why cardinality estimates decide which one you get.

core

Normalization

Functional dependencies, 1NF through BCNF, and the cases where denormalising is right.

core

Buffer Pool

The database's own page cache — why it does not simply trust the OS.