Features

Six store engines: hash, b-tree, FIFO, LIFO, heap and blob. The engine is chosen when the bucket is created.

An engine cannot be changed after the bucket is created, and indexes are declared at creation time.

Evidence: cli/store_types.go:storeTypes· cli/unsupported_features.go:errAlterBucket

Each engine is a different way to read: hash by key, b-tree in key order, FIFO oldest first, LIFO newest first, heap by priority, blob as bytes.

Evidence: cli/store_types.go:storeTypes· store/heap.go:PopItem

Placement is a consistent hash ring keyed by xxHash64. Membership is declarative — there are no elections and no arbiters.

No elections is the same fact as no automatic promotion: losing a node needs an operator.

Evidence: ring/ring.go:Owner· ring/ring.go:AddNode· ring/hasher.go:Sum64

The database is one binary. There is no sidecar and no separate indexer process.

The CLI is a second binary, and it is a client rather than a component of the database.

Evidence: Makefile:build-server· cmd/server/main.go:main

hoardDB-server starts with no arguments and no configuration file.

Evidence: config/config.go:DefaultConfig· TestNoArgumentStartPathInTempDir

On first start it generates a self-signed TLS keypair and serves over TLS.

The certificate is self-signed: a first client connection trusts it on first use and records its fingerprint. It is not a CA-issued certificate.

Evidence: transport/transport.go:LoadOrCreateKeys· transport/transport.go:GenerateEd25519Keys

Authentication is always required. There is no flag that turns it off.

The CLI's -insecure flag is a client-side TLS verification bypass. It is not a server authentication switch, and there is no server-side equivalent.

Evidence: server/auth.go:NewCredential· server/authz.go:authorize

A root credential is generated on the first start and written to ./data/root.password at mode 0600.

Evidence: server/authkey.go:LoadOrCreateRootPassword· proof/five-minute-path.out

Passwords are hashed with Argon2id.

Evidence: server/auth.go:NewCredential

Replication is in the binary and free: replication factor, write-ahead log, and a write concern of one, majority or all.

hoardDB never promotes or removes a node automatically. Losing a node needs an operator. Replication is off until a replication factor above one is configured.

Off by default Evidence: config/config.go:ReplicationFactor· storage/wal.go:WAL· server/write_concern.go:WriteConcernLevel· docs/user/limitations.md#cluster

Audit logging is in the server and free.

It is off by default — turn it on in the configuration.

Off by default Evidence: server/audit.go:AuditLogger· config/config.go:AuditConfig

Users, roles and per-database grants are persisted and enforced.

A role change applies at the next authentication, not to a connection that is already open.

Evidence: server/authz.go:roleSatisfies· server/users.go:LoadUsersConfig

dump and restore write ordinary BSON that other tools can read.

Blob payloads and user accounts are not included in a dump.

Evidence: cli/dump.go:RunDumpCommand· cli/dump.go:RunRestoreCommand

hoardDB is not MongoDB wire-compatible and does not aim to be. HQL is inspired by MongoDB's syntax; it is a different language.

Evidence: cli/parser.go:ParseCommand

hoardDB is pre-1.0. Expect breaking changes.

Evidence: docs/user/limitations.md

MongoDB's own reference for mongod says --noauth is currently the default.

Evidence: https://www.mongodb.com/docs/manual/reference/program/mongod/ (fetched 2026-09-20)

MongoDB's free self-managed search runs as a separate mongot process.

Evidence: https://www.mongodb.com/docs/search/self-managed/current/deployment/compatibility-requirements/ (fetched 2026-09-20)

Encryption at rest and auditing are MongoDB Enterprise features.

Evidence: https://www.mongodb.com/docs/manual/core/security-encryption-at-rest/ (fetched 2026-09-20)

MongoDB's multi-document transactions require a replica set or a sharded cluster; a standalone rejects them.

Evidence: https://www.mongodb.com/docs/manual/core/transactions/ (fetched 2026-09-20)