Database Schema Reference

Database Schema Reference

TMI uses two primary data stores: PostgreSQL for persistent data and Redis for real-time collaboration and caching.

PostgreSQL Schema

PostgreSQL stores the core threat modeling data including threat models, diagrams, threats, users, and authorization information.

For complete PostgreSQL schema documentation, see:

• PostgreSQL Schema Documentation

Key Tables

The schema includes tables for:

• Threat Models - Top-level threat modeling documents
• Diagrams - Data flow diagrams associated with threat models
• Threats - Identified threats and risks
• Elements - Components in diagrams (processes, data stores, actors)
• Data Flows - Connections between elements
• Users - User accounts and authentication
• Authorization - Role-based access control (owner, writer, reader)
• Metadata - Custom key-value extensions

Schema Management

# View schema in PostgreSQL
psql -U postgres -d tmi -c "\dt"

# Export schema
pg_dump -U postgres -d tmi --schema-only > schema.sql

Redis Schema

Redis provides real-time collaboration features, including:

• WebSocket Connection Management - Track active client connections
• Diagram Edit Locks - Prevent concurrent edit conflicts
• Real-time Notifications - Broadcast changes to connected clients
• Session Cache - Store active user sessions
• Temporary Data - Store data in progress before persistence

For complete Redis schema documentation, see:

• Redis Schema Documentation

Key Redis Structures

• WebSocket Session Keys - ws:session:{sessionId}
• Diagram Locks - lock:diagram:{diagramId}
• Change Queues - changes:{diagramId}
• User Sessions - user:session:{userId}

Redis Operations

# Connect to Redis
redis-cli

# View all keys
KEYS *

# Monitor real-time activity
MONITOR

Schema Evolution

Migrations

The TMI project manages schema changes through migrations. All database changes are version-controlled.

Backup and Recovery

See Database-Operations for backup and recovery procedures.

Performance Considerations

• PostgreSQL indexes are defined on frequently queried columns
• Redis keys expire automatically based on TTL
• Consider partitioning large tables in high-volume deployments

Related Documentation

• Database-Operations - Operational procedures
• Performance-and-Scaling - Optimize schema for scale
• PostgreSQL Operations Guide

Access Control

Authorization information is stored in the authorization field of each object:

• Owner - Full read/write/delete permissions
• Writer - Read and write permissions
• Reader - Read-only permissions

See Glossary for "Authorization" for detailed permission rules.