Document Store: Introduction

Document Store: Introduction

Part of: HeliosDB Document Store User Guide

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What is a Document Store?

A document store is a type of NoSQL database that stores data as JSON-like documents. Unlike traditional relational databases with rigid schemas, document stores offer:

• Flexible schemas: Each document can have different fields
• Nested structures: Store complex hierarchical data naturally
• Array support: First-class support for lists and collections
• Dynamic fields: Add/remove fields without migrations
• Natural mapping: JSON maps directly to application objects

Why HeliosDB Document Store?

HeliosDB’s Document Store combines the flexibility of MongoDB with enterprise-grade features:

Feature	HeliosDB	MongoDB	PostgreSQL JSONB
MongoDB Compatibility	80% wire protocol	100%	0%
ACID Transactions	Multi-document	⚠ Limited	Full
Query Performance	<5ms (indexed)	10-20ms	8-15ms
Write Throughput	120K docs/sec	50-80K	30-50K
Schema Validation	JSON Schema		⚠ Limited
Change Streams	Real-time		⚠ Triggers only
Full-Text Search	Integrated	Atlas Search
Geospatial Queries	2dsphere		PostGIS
Multi-Model	SQL+Document+Graph	❌	SQL+JSONB

Key Differentiators:

1. True ACID: Multi-document transactions with full ACID guarantees
2. Sub-5ms queries: Indexed queries complete in <5ms (P99)
3. 120K writes/sec: Batch inserts achieve 120K documents/second
4. SQL Integration: Query documents using SQL or MongoDB query language
5. Unified Platform: One database for relational, document, and graph data
6. PostgreSQL JSONB: 100% compatible with PostgreSQL JSONB operators

MongoDB Wire Protocol Compatibility (80%)

HeliosDB supports the MongoDB wire protocol, allowing you to use existing MongoDB drivers:

Supported Operations:

• CRUD: insert, find, update, delete, replace
• Aggregation: $match, $group, $project, $sort, $limit, $lookup, $unwind
• Indexes: single-field, compound, text, geospatial
• Transactions: multi-document ACID transactions
• Change Streams: real-time notifications
• Authentication: SCRAM-SHA-256

Not Yet Supported (coming in v6.1):

• ⚠ GridFS (large file storage)
• ⚠ Sharded clusters (distributed collections)
• ⚠ Some advanced aggregation stages ($graphLookup, $facet)

PostgreSQL JSONB Compatibility

HeliosDB’s document store is built on PostgreSQL-compatible JSONB:

-- PostgreSQL JSONB operators work directly
SELECT * FROM documents WHERE data @> '{"status": "active"}';
SELECT * FROM documents WHERE data->>'name' = 'Alice';
SELECT * FROM documents WHERE data->'tags' ? 'important';

-- HeliosDB extensions
SELECT * FROM documents WHERE data @@ '$.user.age > 25';

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