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HeliosDB Nano v2.4.0 Release Notes

HeliosDB Nano v2.4.0 Release Notes

Release Date: November 25, 2025 Status: Beta Release Version: v2.4.0-beta

Executive Summary

HeliosDB Nano v2.4.0-beta represents a major milestone in the evolution of our embedded database, successfully implementing Phase 3 features including advanced vector compression, enterprise SQL capabilities, and comprehensive performance optimizations.

Key Achievements

  • ✅ Product Quantization: 8-16x vector compression with 95-98% accuracy maintained
  • ✅ Database Branching: Full CREATE/DROP/MERGE BRANCH SQL support
  • ✅ Time-Travel Queries: AS OF TIMESTAMP for historical data access
  • ✅ Materialized Views: Incremental refresh with CPU-aware scheduling
  • ✅ Advanced Compression: FSST string and ALP numeric compression
  • ✅ System Views: PostgreSQL-compatible pg_* views
  • ✅ Test Coverage: 95.1% test pass rate (527/554 tests)
  • ✅ Clean Build: Zero compilation errors

Major Features

1. Vector Search Enhancements

Product Quantization (PQ)

  • Compression Ratio: 8-16x reduction in memory usage
  • Accuracy: 95-98% recall maintained
  • Performance: 5-10x faster search on large datasets
  • Implementation: K-means++ training with asymmetric distance computation

Quantized HNSW Index

  • Seamless integration with existing vector search
  • Automatic memory optimization
  • Configurable compression levels
  • Real-time compression statistics

2. Database Branching

Complete SQL support for database branching:

-- Create development branch
CREATE DATABASE BRANCH dev FROM main AS OF NOW;


-- Work in isolated branch
USE DATABASE BRANCH dev;


-- Merge changes back
MERGE DATABASE BRANCH dev INTO main;


-- Clean up
DROP DATABASE BRANCH dev;

Features:

  • Zero-copy branching via RocksDB snapshots
  • Automatic conflict detection
  • Three-way merge support
  • Branch metadata tracking

3. Time-Travel Queries

Query historical data at any point in time:

-- Query data as it was 1 hour ago
SELECT * FROM users AS OF TIMESTAMP '2025-11-25 08:00:00';


-- Compare current vs historical
SELECT * FROM inventory AS OF TIMESTAMP NOW() - INTERVAL '1 DAY';


-- Use relative timestamps
SELECT * FROM orders AS OF TIMESTAMP NOW() - INTERVAL '7 DAYS';

Capabilities:

  • 7-day retention by default (configurable)
  • Automatic garbage collection
  • Minimal storage overhead
  • Sub-second time travel

4. Materialized Views with Auto-Refresh

Intelligent materialized view management:

-- Create incrementally refreshing view
CREATE MATERIALIZED VIEW sales_summary AS
SELECT date, SUM(amount) as total
FROM sales
GROUP BY date
WITH (
    refresh_interval = '1 HOUR',
    incremental = true
);


-- Manual refresh
REFRESH MATERIALIZED VIEW sales_summary;

Features:

  • CPU-aware scheduling
  • Incremental refresh support
  • Delta change tracking
  • Automatic dependency resolution

5. Advanced Compression

FSST (Fast Static Symbol Table)

  • 2-4x compression for string data
  • 500+ MB/sec compression speed
  • 2+ GB/sec decompression speed
  • Automatic dictionary training

ALP (Adaptive Lossless floating-Point)

  • 30-50% compression for numeric data
  • Preserves full precision
  • SIMD-accelerated operations
  • Automatic pattern detection

Performance Improvements

Benchmark Results

Operationv2.3.1v2.4.0Improvement
Vector Insert50K/sec125K/sec2.5x
Vector Search (1M vectors)2.5ms0.5ms5x
Compression RatioN/A8-16xNew
Memory Usage (1M vectors)3GB375MB8x
Time-Travel QueryN/A<100msNew
Branch CreationN/A<10msNew

Breaking Changes

API Changes

  1. Database renamed to EmbeddedDatabase for clarity
  2. Vector index configuration now requires explicit PQ settings
  3. Some internal modules reorganized (shouldn’t affect most users)

Removed Features

  1. HTTP sync server (deprecated, use branching instead)
  2. JWT authentication (moved to enterprise edition)
  3. Legacy sync protocol (incompatible with v2.3.x)

Known Issues

Beta Limitations

  1. Vector Quantization: Some edge cases in high-dimensional spaces (>1024 dims)
  2. Compression: FSST may not optimize for very short strings (<10 chars)
  3. Branching: Cannot merge branches with schema conflicts
  4. Time-Travel: Performance degrades with >1M historical versions

Test Failures (27 total)

  • 5 vector quantization edge cases
  • 8 advanced compression scenarios
  • 6 sync protocol tests (feature disabled)
  • 8 integration tests (being addressed)

Migration Guide

From v2.3.1

  1. Update imports:
// Old
use heliosdb_nano::Database;


// New
use heliosdb_nano::EmbeddedDatabase;
  1. Enable new features:
let config = Config::default()
    .with_vector_compression(true)
    .with_time_travel(true)
    .with_branching(true);
  1. Update vector indices:
// Enable compression for existing indices
db.execute("ALTER INDEX vec_idx SET (compression = 'pq')")?;

Future Roadmap (v2.5.0)

Planned Features

  1. Distributed consensus: Raft-based replication
  2. Streaming aggregations: Real-time analytics
  3. Graph traversals: Native graph operations
  4. ML inference: Built-in model serving
  5. Cloud native: S3/GCS storage backends

Performance Goals

  • 1M+ vectors/sec insert rate
  • <100μs p99 latency for searches
  • 20x compression for time-series data
  • Zero-overhead branching

Documentation

Updated Guides

Examples

Acknowledgments

This release represents months of intensive development and wouldn’t have been possible without the dedication of our team and the valuable feedback from our community.

Special thanks to:

  • The DuckDB team for FSST/ALP compression algorithms
  • The Faiss team for product quantization insights
  • Our beta testers for invaluable feedback

Support

Resources

License

HeliosDB Nano is licensed under the MIT License.

HeliosDB Nano v2.4.0-beta - Built for the future of embedded databases