Overview

Data Isolation Principles define how to keep tenant data separate in multi-tenant systems. They focus on scoping queries, indexing with tenant identifiers, and using tenant-aware encryption keys to prevent cross-tenant access. Following them supports security and regulatory compliance.

How This Skill Works

The principles mandate tenant-scoped queries, ensuring data access is filtered by tenantId. They require every index to include tenantId for efficient, isolated lookups, and encryption keys to be tenant-aware to prevent cross-tenant decryption. Practically, implement a tenantId filter in queries, extend indexes with tenantId, and manage keys per tenant with proper access controls.

When to Use It

• Designing or auditing a multi-tenant database schema and access controls
• Onboarding new tenants with isolated data boundaries
• Strengthening security and compliance in a SaaS application
• Investigating data access patterns and establishing tenant-specific auditing
• Refactoring or migrating data to enforce stronger data isolation

Quick Start

1. Step 1: Add a tenantId field to all data models and ensure all queries filter by the current tenantId
2. Step 2: Extend or create indexes to include tenantId and verify query plans use them
3. Step 3: Implement tenant-aware encryption keys and enforce per-tenant key access via your KMS

Best Practices

• Always scope every query by tenantId to prevent cross-tenant data leakage
• Include tenantId in every index to support efficient tenant-scoped lookups
• Use tenant-aware encryption keys managed by a robust KMS
• Enforce tenant context at the application layer and in data-access services
• Regularly review access logs and key usage for anomalous, cross-tenant activity

Example Use Cases

• A SaaS CRM ensures all data queries include a tenantId filter, isolating customer data by tenant
• Indexes are defined with tenantId to enable fast, tenant-scoped queries
• Encryption keys are bound to each tenant and retrieved via a tenant-aware KMS
• Audit logs show only tenant-scoped data access and no cross-tenant reads
• Tenant onboarding includes migrations that append tenantId to existing records and update access controls

Frequently Asked Questions