Gallery

Every exhibit on display

Interactive filter by paradigm, family, or free-text search. Each card links to a full exhibit page with diagrams, walk-throughs, and short code excerpts. Sort is by initial release year.

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Paradigm

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Showing 25 of 25 exhibits

client-serverest. 1996

PostgreSQL

The most-extensible open-source RDBMS: MVCC, a cost-based planner, and 30+ years of catalog evolution.

Architecture: process per connectionIsolation: MVCC + SSIIndexes: B-tree, hash, GIN, BRIN, GiST

embedded-sqlest. 2000

SQLite

The most-deployed database in the world: a single-file SQL engine with WAL, MVCC, and zero ops.

Footprint: < 750 KiBJournal: WAL or rollbackIndexes: B-tree + r-tree + FTS5

serverest. 2005

Apache CouchDB

An append-only document database: B-tree indexes, MVCC revisions, masterless replication.

Model: JSON documents, MVCC revisionsStorage: append-only copy-on-write B-treeIndexes: MapReduce views, incremental

serverest. 2006

Google Bigtable

The original wide-column store: tablets on a distributed lattice, the paper behind HBase and Cassandra.

Model: row key → column families → columnsUnit: tablets (~100-200 MB rows) per serverStorage: SSTable + memtable + tablet log

client-serverest. 2007

Neo4j

A property-graph database with index-free adjacency and Cypher traversals.

Model: nodes + directed relationships + propertiesQuery: Cypher pattern matchingTraversal: index-free adjacency (pointer chase)

serverest. 2008

Apache Cassandra

Wide-column storage at planetary scale: leaderless replication, tunable consistency.

Model: partition key → clustering columnsReplication: leaderless, gossip + tunable QUORUMStorage: commit log → memtable → SSTables

client-serverest. 2009

MariaDB

The community fork of MySQL: pluggable engines, MVCC InnoDB, and columnar storage for analytics.

Default engine: InnoDB (MVCC)Pluggable storage: InnoDB, Aria, ColumnStoreReplication: async + semi-sync + Galera

client-serverest. 2009

MongoDB

A document database: BSON collections, WiredTiger B+ trees, replica sets.

Model: BSON documents in collectionsEngine: WiredTiger: B+ trees + MVCCDurability: journal + snapshot checkpoints

client-serverest. 2009

Redis

An in-memory data-structure server: strings, sets, hashes, sorted sets, streams.

Model: in-memory data structuresExecution: single-threaded command loopPersistence: AOF log + RDB snapshots

serverest. 2009

RethinkDB

The realtime document database: JSON rows, ReQL chaining, and change feeds that push.

Model: JSON documents, ReQL queriesPush: changefeeds — subscribe to queriesSharding: replicate + shard per table

client-serverest. 2010

Elasticsearch

A distributed search engine: inverted indexes, immutable Lucene segments, near-real-time.

Index: inverted: term → postings listStorage: immutable Lucene segmentsVisibility: refresh ≈ every 1s (near-real-time)

embedded-kvest. 2011

RocksDB

An embedded LSM key-value engine built for flash and in-memory workloads.

Write path: WAL + memtable → immutable SSTRead path: memtable → L0 → lower levels, newest firstCompaction: leveled, size-tiered, FIFO

client-serverest. 2011

Couchbase

Memory-first document database: the cache IS the database, persistence is asynchronous.

Model: JSON documents in vBucketsWrite path: memory-first, async persistenceQuery: N1QL — SQL for JSON

serverest. 2012

Amazon DynamoDB

Serverless key-value at any scale: partition-key routing, quorum replication, single-digit ms.

Model: partition key + sort key itemsAccess: GetItem / Query / Scan opsReplication: 3 AZs, quorum writes

serverest. 2013

InfluxDB

A time-series database: measurements, tags, and time-structured merge storage.

Model: measurement + tags + fields + timeStorage: TSM: immutable, time-partitionedLifecycle: retention policies + downsampling

serverest. 2013

etcd

The Raft-consensus key-value store that coordinates Kubernetes — small, watchable, linearizable.

Consensus: Raft — leader + quorum commitsSemantics: linearizable reads, MVCC revisionsWatch: stream changes from any revision

serverest. 2015

CockroachDB

Distributed SQL that survives datacenter loss: Raft ranges, serializable by default.

SQL: Postgres-compatible wire + dialectConsistency: serializable, always onReplication: Raft consensus per range

serverest. 2015

ScyllaDB

Cassandra rebuilt in C++ on a shared-nothing sharded architecture: the same model, lower latency.

Compatible: Cassandra CQL + driversArchitecture: shared-nothing per-core shardsLatency: p99 in single-digit ms

serverest. 2016

ClickHouse

A columnar OLAP engine: sparse primary keys, granule skipping, vectorized scans.

Storage: columnar parts of ~8192-row granulesIndex: sparse primary key (1 entry per granule)Execution: vectorized block processing

serverest. 2017

TimescaleDB

Postgres extended for time series: hypertables, automatic chunking, columnar compression.

Model: hypertables over PostgresPartitioning: automatic time + space chunksCompression: 10-20× columnar on old chunks

embedded-sqlest. 2018

DuckDB

An in-process analytical SQL database: columnar, vectorized, one file, zero servers.

Model: full SQL over columnar storageExecution: vectorized (2048-value batches)Embedded: in-process, single file

serverest. 2018

FoundationDB

A deterministic distributed key-value store proven by simulation before it ever ships.

Design: unbundled: transaction/log/storageTesting: deterministic simulation, fault-injectedSemantics: strictly serializable MVCC

serverest. 2019

QuestDB

Time-series SQL at columnar speed: time-partitioned native storage with SIMD scans.

Ingest: line protocol + ILP over TCP/HTTPStorage: native columnar, time-partitionedOut-of-order: first-class OO updates

server-vectorest. 2021

Qdrant

A Rust-native vector database with payload filtering, HNSW indexes, and distributed consensus.

Index: HNSW + scalar quantizationPayload: filter on any fieldModes: embedded, single, cluster

embedded-vectorest. 2023

LanceDB

A serverless vector database built on the Lance columnar format: fast scans over multimodal data with embedded ANN indexes.

Storage: Lance columnarIndexes: IVF-PQ, HNSWEmbedded + Server: Node, Python, Rust

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