brainy/docs/DATA_MODEL.md
David Snelling 0ddc05a5bb feat: enforce data/metadata separation, numeric range queries, improved docs
- Store data opaquely in add() and update() instead of spreading object
  properties into top-level metadata. data is for semantic search (HNSW),
  metadata is for structured where-filter queries (MetadataIndex).
- Fix numeric range queries in MetadataIndex — use numeric-aware comparison
  instead of lexicographic string comparison for normalized values.
- Add data field to RelateParams and Relation types for relationship content.
- Add where.type → where.noun alias in metadata-only find() path.
- Rewrite README: focused ~350 lines from 791, quick start first, feature
  showcase with mini-snippets, organized doc links, no version callouts.
- Add DATA_MODEL.md and QUERY_OPERATORS.md reference docs.
- Remove 10 outdated/redundant doc files consolidated into API reference.
- Improve JSDoc on Entity, Relation, AddParams, FindParams, and core methods.
- Fix tests asserting data properties appear in metadata (data model violation).
- Deprecate verb.source/target in favor of from/to (public) and sourceId/targetId (storage).
2026-02-09 12:07:54 -08:00

205 lines
7.1 KiB
Markdown

# Data Model
> How Brainy stores entities and relationships, and the critical distinction between `data` and `metadata`.
---
## Entity (Noun)
An entity is the fundamental data unit in Brainy. Every entity has:
| Field | Type | Indexed | Description |
|-------|------|---------|-------------|
| `id` | `string` | Primary key | UUID v4 (auto-generated or custom) |
| `data` | `any` | **HNSW vector index** | Content used for semantic/hybrid search. Strings auto-embed. |
| `metadata` | `object` | **MetadataIndex** | Structured queryable fields (tags, dates, flags, etc.) |
| `type` | `NounType` | MetadataIndex (as `noun`) | Entity type classification |
| `vector` | `number[]` | HNSW | 384-dim embedding (auto-computed from `data` or user-provided) |
| `confidence` | `number` | MetadataIndex | Type classification confidence (0-1) |
| `weight` | `number` | MetadataIndex | Entity importance/salience (0-1) |
| `service` | `string` | MetadataIndex | Multi-tenancy identifier |
| `createdAt` | `number` | MetadataIndex | Creation timestamp (ms since epoch) |
| `updatedAt` | `number` | MetadataIndex | Last update timestamp (ms since epoch) |
| `createdBy` | `object` | MetadataIndex | Source augmentation info |
### Example
```typescript
const id = await brain.add({
data: 'John Smith is a software engineer at Acme Corp', // → embedded into vector
type: NounType.Person,
metadata: { // → indexed, queryable via where filters
role: 'engineer',
department: 'backend',
yearsExperience: 8
},
confidence: 0.95,
weight: 0.7
})
```
---
## Relationship (Verb)
A relationship is a typed, directed edge connecting two entities.
| Field | Type | Indexed | Description |
|-------|------|---------|-------------|
| `id` | `string` | Primary key | UUID v4 (auto-generated) |
| `from` | `string` | **GraphAdjacencyIndex** | Source entity ID |
| `to` | `string` | **GraphAdjacencyIndex** | Target entity ID |
| `type` | `VerbType` | GraphAdjacencyIndex (as `verb`) | Relationship type classification |
| `data` | `any` | — | Opaque content (overrides auto-computed vector if provided) |
| `metadata` | `object` | — | Structured fields on the edge |
| `weight` | `number` | — | Connection strength (0-1, default: 1.0) |
| `confidence` | `number` | — | Relationship certainty (0-1) |
| `evidence` | `RelationEvidence` | — | Why this relationship was detected |
| `createdAt` | `number` | — | Creation timestamp (ms since epoch) |
| `updatedAt` | `number` | — | Last update timestamp (ms since epoch) |
| `service` | `string` | — | Multi-tenancy identifier |
### Example
```typescript
const relId = await brain.relate({
from: personId,
to: projectId,
type: VerbType.WorksOn,
data: 'Lead engineer on the AI module', // Optional: content for this edge
metadata: { // Optional: queryable edge fields
role: 'lead',
startDate: '2024-01-15'
},
weight: 0.9
})
```
---
## Data vs Metadata
This is the most important concept in Brainy's storage model:
### `data` — Content for Semantic Search
- Embedded into a 384-dimensional vector via the WASM embedding engine
- Searchable via **semantic similarity** (HNSW vector index) and **hybrid text+semantic** search
- Queried by passing `query` to `find()`:
```typescript
brain.find({ query: 'machine learning algorithms' })
```
- **NOT** indexed by MetadataIndex — you cannot use `where` filters on `data`
- Stored opaquely: strings, objects, numbers — anything goes
### `metadata` — Structured Queryable Fields
- Indexed by MetadataIndex with O(1) lookups per field
- Queryable via `where` filters using [BFO operators](./QUERY_OPERATORS.md):
```typescript
brain.find({
where: {
department: 'engineering',
yearsExperience: { greaterThan: 5 },
tags: { contains: 'senior' }
}
})
```
- **NOT** used for vector/semantic search
- Must be a flat or lightly nested object
### Quick Reference
| | `data` | `metadata` |
|---|---|---|
| **Purpose** | Content for embedding / semantic search | Structured fields for filtering |
| **Searched by** | `find({ query })` — vector similarity, hybrid text+semantic | `find({ where })` — exact, range, set operators |
| **Indexed by** | HNSW vector index | MetadataIndex |
| **Queryable with operators?** | No | Yes (`equals`, `greaterThan`, `oneOf`, etc.) |
| **Auto-embedded?** | Yes (strings → 384-dim vectors) | No |
| **Typical content** | Text descriptions, document content | Tags, dates, status flags, categories, numeric fields |
### Common Pattern
```typescript
// Add an article
await brain.add({
data: 'A deep dive into transformer architectures and attention mechanisms',
type: NounType.Document,
metadata: {
title: 'Transformer Deep Dive',
author: 'Dr. Chen',
publishedYear: 2024,
tags: ['AI', 'transformers', 'NLP'],
status: 'published'
}
})
// Search by content (semantic — searches data)
const results = await brain.find({ query: 'neural network attention' })
// Filter by fields (exact — queries metadata)
const recent = await brain.find({
where: {
publishedYear: { greaterThan: 2023 },
status: 'published'
}
})
// Combine both (Triple Intelligence)
const precise = await brain.find({
query: 'attention mechanisms', // Semantic search on data
where: { author: 'Dr. Chen' }, // Metadata filter
connected: { from: authorId, depth: 1 } // Graph traversal
})
```
---
## Storage Field Naming
Internally, Brainy uses different field names in storage vs the public API:
| Public API (Entity/Relation) | Storage (metadata object) | Notes |
|------------------------------|--------------------------|-------|
| `type` | `noun` | Entity type stored as `noun` |
| `from` | `sourceId` | Relationship source |
| `to` | `targetId` | Relationship target |
| `type` (on Relation) | `verb` | Relationship type stored as `verb` |
When querying with `find()`, you can use:
- `type` parameter (convenience alias, equivalent to `where.noun`)
- `where.noun` directly
```typescript
// These are equivalent:
brain.find({ type: NounType.Person })
brain.find({ where: { noun: NounType.Person } })
```
---
## Standard Metadata Fields
When you add an entity, Brainy stores these standard fields in the metadata object alongside your custom fields:
| Field | Set By | Description |
|-------|--------|-------------|
| `noun` | System | Entity type (NounType enum value) |
| `data` | System | The raw `data` value (stored opaquely) |
| `createdAt` | System | Creation timestamp |
| `updatedAt` | System | Last update timestamp |
| `confidence` | User | Type classification confidence |
| `weight` | User | Entity importance |
| `service` | User | Multi-tenancy identifier |
| `createdBy` | User/System | Source augmentation |
On read, these standard fields are extracted to top-level Entity properties. The `metadata` field on the returned Entity contains **only your custom fields**.
---
## See Also
- [API Reference](./api/README.md) — Complete API documentation
- [Query Operators](./QUERY_OPERATORS.md) — All BFO operators with examples
- [Find System](./FIND_SYSTEM.md) — Natural language find() details