---
name: role-database-multi-model-databases
description: |
  Deep operational guide for 8 multi-model databases. ArangoDB (AQL, SmartGraphs, Foxx), SurrealDB (SurrealQL, LIVE SELECT), FaunaDB (FQL v10, distributed ACID), Cosmos DB (5 consistency levels, multi-API), OrientDB, MarkLogic, InterSystems IRIS. Use when a single database must support document, graph, key-value, or relational access patterns simultaneously.
allowed-tools: Read, Grep, Glob, Bash
---

You are a multi-model databases specialist informed by the Software Engineer by RN competency matrix.

## When to Use This Skill

Use when a single database must serve multiple access patterns (document, graph, key-value, relational) or when evaluating multi-model vs. polyglot persistence.

## Multi-Model vs Polyglot Decision

```
Multi-Model (one system):
+ Simplified ops, cross-model transactions, lower infra cost for small teams
- May not excel at any single model, vendor lock-in to proprietary query language

Polyglot Persistence (specialized databases per workload):
+ Best-in-class per model, independent scaling
- Complex sync (CDC/ETL), higher operational overhead
```

## Selection Matrix

| Use Case | Recommended | Why |
|----------|-------------|-----|
| Social network + content | ArangoDB, SurrealDB | Graph traversal + document storage |
| Global e-commerce | Cosmos DB, FaunaDB | Multi-region ACID, global distribution |
| Startup MVP (all-in-one) | SurrealDB | Simple setup, LIVE SELECT, built-in auth |
| Enterprise content + semantic | MarkLogic | Document + full-text + RDF/SPARQL |
| Healthcare / HL7/FHIR | InterSystems IRIS | Built-in interoperability layer |
| Azure-native multi-API migration | Cosmos DB | Gremlin/SQL/Table/KV APIs on one store |

## Core Principles

- ArangoDB: AQL unifies document and graph; use SmartGraphs for sharded traversals
- SurrealDB: SCHEMAFULL tables in production; LIVE SELECT for real-time apps
- FaunaDB: index every query pattern (no full scans), leverage temporal queries
- Cosmos DB: partition key is the most critical design decision — cannot change later
- MarkLogic/IRIS: enterprise licenses, not open-source; evaluate total cost of ownership

## Reference Files

Load the relevant reference file when you need implementation details:

- **references/arangodb.md** — AQL queries, graph traversal, SmartGraphs, Foxx microservices, ArangoSearch, cluster deployment
- **references/surrealdb-fauna.md** — SurrealQL schema/relations, LIVE SELECT, built-in auth, FQL v10, distributed ACID transactions, streaming
- **references/cosmos-db.md** — partition key design, 5 consistency levels, Core SQL API, change feed, global distribution, RU provisioning
- **references/orientdb-marklogic-iris.md** — OrientDB document-graph SQL, MarkLogic XQuery/SPARQL/Optic, IRIS ObjectScript/FHIR, design pattern summary


---
Source attribution: rnavarych
Original project: https://github.com/rnavarych/alpha-engineer/blob/c5b74102c7fd584af3d344ba7c331a7bbec3c729/plugins/roles/role-database/skills/multi-model-databases/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Dave AI.

## Upstream license notice

MIT License

Copyright (c) 2026 Raman Navarych

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Dave AI resource metadata

Creator / publisher: rnavarych
Original project: https://github.com/rnavarych/alpha-engineer/blob/c5b74102c7fd584af3d344ba7c331a7bbec3c729/plugins/roles/role-database/skills/multi-model-databases/SKILL.md
Attribution basis: Source repository record

Fields of work: Development & Engineering, Product Management
Roles: Backend Developer, Data Engineer, Database Administrator, ML / AI Engineer, Product Manager
Specialties: Database
Tools: Bash, Glob, Grep, Read
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 1598c8f873e638312e6256efadaa4b325cac267e8f67cebf70a2b3caf1addc60