HeliosDB-Lite Feature Flags

HeliosDB-Lite Feature Flags

Quick Reference

# Default build (encryption + vector search + ring crypto)
cargo build

# With FIPS-compliant crypto
cargo build --features fips

# With HA proxy (all proxy features)
cargo build --features ha-standard

# Everything
cargo build --features ha-full

# Sync module (experimental)
cargo build --features sync-experimental

Default Features

These are enabled by default (cargo build with no flags):

Feature	Description
encryption	TDE (AES-256-GCM) transparent data encryption
vector-search	HNSW index, PQ compression, distance functions
ring-crypto	Ring cryptographic provider (default)

Core Features (opt-in)

Feature	Description	Dependencies
simd	SIMD-accelerated vector operations	None
fips	AWS-LC FIPS 140-2 cryptographic provider	aws-lc-rs
gssapi	Kerberos/GSSAPI authentication	libgssapi
rocksdb-backend	RocksDB storage backend (legacy)	rocksdb
sync-experimental	Multi-node sync module	None
server	Server-mode with async runtime	None
test-utils	Test utilities for integration tests	None
internal-tests	Internal API tests (not public)	None

HA Features

Tier Hierarchy

ha-tier1 (WAL streaming replication)
  └── ha-tier2 (multi-primary replication)
       └── ha-branch-replication (branch-level replication)

ha-tier3 (sharding)

ha-innovations (base innovation module)
  ├── ha-proxy (proxy with 15 features)
  ├── ha-dedup (deduplication)
  └── ha-ab-testing (A/B testing)

Proxy Features (all require ha-proxy)

Feature	Description
pool-modes	Connection pool modes (transaction, session, statement)
query-cache	Query result caching at proxy level
routing-hints	SQL hint-based query routing
lag-routing	Lag-aware read routing to replicas
rate-limiting	Request rate limiting per connection
circuit-breaker	Circuit breaker for failing backends
query-analytics	Query analytics and slow query logging
multi-tenancy	Multi-tenant isolation at proxy level
auth-proxy	Authentication proxy (LDAP, OAuth)
query-rewriting	Automatic query rewriting rules
wasm-plugins	WebAssembly plugin extension system
graphql-gateway	GraphQL API gateway
schema-routing	Schema-based query routing
distribcache	Distributed caching layer

Convenience Bundles

Bundle	Includes
ha-standard	tier1 + tier2 + proxy + all 14 proxy features
ha-full	ha-standard + tier3 + innovations + dedup + ab-testing + branch-replication

Decision Tree

Which features do I need?

Embedded database (no network)?

• Default features are sufficient
• Add simd for faster vector operations
• Add fips if you need FIPS 140-2 compliance

Single-server with PostgreSQL protocol?

• Add server for async runtime
• Default crypto is fine for most uses

Multi-node replication?

• ha-tier1 for primary-replica WAL streaming
• ha-tier2 for multi-primary (adds conflict resolution)
• ha-tier3 for horizontal sharding

Load balancer / proxy?

• ha-proxy is the base, then add specific features:
  • ha-standard for all proxy features
  • Or pick individual: pool-modes, query-cache, rate-limiting, etc.

Plugin extensibility?

• wasm-plugins for WebAssembly extensions
• graphql-gateway for GraphQL API

Compatibility Matrix

Feature A	Feature B	Compatible?	Notes
ring-crypto	fips	Either/or	Use one crypto provider
encryption	fips	Yes	FIPS replaces Ring for crypto ops
ha-tier1	ha-tier2	Yes	tier2 includes tier1
ha-tier3	ha-tier1/2	Yes	Independent sharding layer
sync-experimental	ha-*	Not tested	Sync module is separate from HA
rocksdb-backend	default	Yes	Opt-in alternative storage