Dms Data Integrity Foreign Keys Triggers

What the recommended solution is

During homogeneous and heterogeneous migrations using Database Migration Service (DMS), managing secondary database objects such as foreign keys and triggers on the target database is essential for smooth data replication. Disabling or dropping these constraints during the initial dump and continuous CDC replication ensures that dependencies and automated logic do not disrupt data movement.

How it addresses the migration requirements

• Resolves Foreign Key Violations: Database Migration Service does not guarantee transactional ordering across multiple tables during data ingestion. Consequently, child tables may load before parent tables, triggering constraint violations if foreign keys are active. Dropping foreign keys on the destination (or utilizing the REPLICATION role privilege) avoids these constraint validation errors.
• Prevents Duplicate Trigger Execution: Replicated data captured by Change Data Capture (CDC) on the source database already reflects the business logic and state changes produced by source triggers. If triggers are left enabled on the destination database, they will execute a second time upon record insertion, leading to data corruption or duplicate rows.
• Ensures Integrity Post-Cutover: Re-creating foreign keys and triggers once migration and final cutover are complete restores full relational integrity and business rule enforcement for application traffic.

Key advantages and capabilities

• Prevents Replication Halts: Eliminates blocking errors caused by parent-child relational dependencies during parallel table loading.
• Maintains Consistent State: Avoids unauthorized mutations or data duplication on destination tables by suppressing double execution of triggers.
• Streamlined Workflow: Supports bypassing enforcement via built-in PostgreSQL database options such as the REPLICATION attribute for the migration user.

Why this is optimal

This approach directly targets the architectural mechanics of DMS, which streams table snapshots and log changes independently. By deferring foreign key validation and trigger execution until data transfer stabilizes, the migration pipeline completes reliably without data corruption.