---
title: "Features Overview"
---

# Features Overview

HeliosDB Nano provides advanced database features typically found in enterprise systems, all in a lightweight embedded package.

## Core Features

### Database Branching
Create isolated database branches for development, testing, or experimentation without duplicating data. Similar to Git branches for your database.

[:octicons-arrow-right-24: Branching Guide](https://www.heliosdb.com/docs/nano/features/branching/)

### Time-Travel Queries
Query data as it existed at any point in time using `AS OF TIMESTAMP` syntax. Useful for auditing, debugging, and historical analysis.

[:octicons-arrow-right-24: Time-Travel Guide](https://www.heliosdb.com/docs/nano/features/time-travel/)

### Materialized Views
Create pre-computed views with automatic or incremental refresh. CPU-aware scheduling prevents system overload.

[:octicons-arrow-right-24: Materialized Views Guide](https://www.heliosdb.com/docs/nano/features/materialized-views/)

### Vector Search
Built-in HNSW vector indexing for similarity search, RAG applications, and AI/ML workloads. Supports product quantization for memory efficiency.

[:octicons-arrow-right-24: Vector Search Guide](https://www.heliosdb.com/docs/nano/features/vector-search/)

## Security Features

### Row-Level Security (RLS)
Fine-grained access control at the row level. Essential for multi-tenant applications.

[:octicons-arrow-right-24: RLS Guide](https://www.heliosdb.com/docs/nano/features/rls/)

### Encryption at Rest
AES-256-GCM transparent data encryption with secure key management.

[:octicons-arrow-right-24: Encryption Guide](https://www.heliosdb.com/docs/nano/features/encryption/)

### Multi-Tenancy
Built-in tenant isolation with quotas, plans, and CDC support.

[:octicons-arrow-right-24: Multi-Tenancy Guide](https://www.heliosdb.com/docs/nano/features/multi-tenancy/)

## Performance Features

### Self-Maintaining Filter Index (SMFI)
Automatic bloom filters and zone maps for storage-level filtering. Speculatively creates indexes based on query patterns.

[:octicons-arrow-right-24: SMFI Guide](https://www.heliosdb.com/docs/nano/features/storage-filtering/)

### Per-Column Storage & Compression
FSST (string) and ALP (numeric) compression with per-column configuration for optimal storage efficiency.

[:octicons-arrow-right-24: Per-Column Storage Guide](https://www.heliosdb.com/docs/nano/features/per-column-storage/)

## SQL Features

### Triggers
PostgreSQL-compatible triggers for automating database operations in response to INSERT, UPDATE, and DELETE events.

[:octicons-arrow-right-24: Triggers Guide](https://www.heliosdb.com/docs/nano/features/triggers/)

### Procedural Language (PL)
Multi-dialect procedural language supporting PL/pgSQL, T-SQL, PL/SQL, and DB2 SQL PL for stored procedures and functions.

[:octicons-arrow-right-24: PL Guide](https://www.heliosdb.com/docs/nano/features/procedural-language/)

### Primary Keys
Unique row identification with automatic indexing and NOT NULL constraints.

[:octicons-arrow-right-24: Primary Keys Guide](https://www.heliosdb.com/docs/nano/features/primary-keys/)

### Foreign Keys
Referential integrity constraints with CASCADE, SET NULL, and DEFERRED enforcement modes.

[:octicons-arrow-right-24: Foreign Keys Guide](https://www.heliosdb.com/docs/nano/features/foreign-keys/)

## High Availability

### HA Tier 1-3
Multi-tier high availability with warm standby (Tier 1), multi-primary replication (Tier 2), and sharding (Tier 3).

[:octicons-arrow-right-24: HA Guide](https://www.heliosdb.com/docs/nano/features/high-availability/)

## Feature Comparison

| Feature | HeliosDB Nano | SQLite | PostgreSQL |
|---------|---------------|--------|------------|
| Embedded Mode | Yes | Yes | No |
| Server Mode | Yes | No | Yes |
| Database Branching | Yes | No | No |
| Time-Travel | Yes | No | No |
| Vector Search | Yes | No | Extension |
| Row-Level Security | Partial (embedded API and REPL) | No | Yes |
| Materialized Views | Yes | No | Yes |
| Triggers | Partial (BEFORE-row assignments) | Yes | Yes |
| Procedural Language | Partial (SQL and simple PL/pgSQL) | No | Yes |
| Primary Keys | Yes | Yes | Yes |
| Foreign Keys | Yes | Yes | Yes |
| Per-Column Compression | Yes | No | No |
| HA (Multi-Tier) | Yes | No | Extension |
| Transparent Write Routing (TWR) | Planned | No | No |

## Feature Index

For developers looking for source code locations, see the [Feature Index](https://www.heliosdb.com/docs/nano/developer/feature-index/).