Catalog
concept#Data#Architecture#Integration#Platform

Database Migration

Concept for the planned transfer of schema and data between database systems or versions, including validation and cutover strategies.

Database migration is the process of transferring data and schema between database systems or versions.
Established
High

Classification

  • High
  • Technical
  • Architectural
  • Intermediate

Technical context

Replication and CDC tools (e.g. Debezium)CI/CD pipelines for migration scriptsMonitoring and observability tools

Principles & goals

Treat migration as a planned, tested process with clear acceptance criteria.Minimize downtime using replication and phased cutover plans.Treat schema changes as versioned artifacts and automate verification steps.
Build
Domain, Team

Use cases & scenarios

Compromises

  • Data loss or inconsistencies from faulty transformations.
  • Unforeseen performance regressions in the target system.
  • Extended downtime due to insufficient planning.
  • Version schema changes and migration scripts in SCM.
  • Automate validation checks in CI pipelines.
  • Prepare clear rollback paths and test data for rollbacks.

I/O & resources

  • Schema definitions and dependencies
  • Sample data and data profiling
  • Test and staging environments
  • Target schemas and migration scripts
  • Validation and acceptance reports
  • Cutover and rollback plans

Description

Database migration is the process of transferring data and schema between database systems or versions. It covers schema evolution, data transformation, validation, and cutover strategies. The concept addresses compatibility, downtime minimization, and operational coordination across teams and environments. It informs planning, tooling, and rollback options.

✔

  • Enables technology changes and cost optimization.
  • Improves scalability and maintainability via modern target platforms.
  • Reduces operational overhead for managed or cloud targets.

✖

  • Complexity with heterogeneous engines and proprietary features.
  • High testing effort for data consistency and performance.
  • Requires organizational coordination between SRE, DBAs and development.

  • Downtime

    Measured time the application is unavailable.

  • Data inconsistencies

    Count or share of records with inconsistencies after migration.

  • Migration throughput

    Volume of data migrated per time unit successfully.

Migration to managed cloud database

Company moved OLTP database to a managed service, reduced operational overhead and used replication for minimal outage.

Heterogeneous engine migration (Oracle → PostgreSQL)

Conversion of procedures and data formats, use of transformation layers and extensive testing to ensure functionality.

Zero-downtime schema refactor

Phased rollout using feature flags and replication, with automated consistency checks during migration.

1

Inventory and dependency analysis

2

Design target schema and transformation mapping

3

Set up test and replication environments

4

Implement automated tests and validations

5

Perform dry runs and performance tests

6

Production cutover and monitoring

⚠️ Technical debt & bottlenecks

  • Legacy schema that is undocumented or denormalized.
  • Ad-hoc migration scripts without tests or CI integration.
  • Missing automation for validation and rollback.
Network bandwidthStorage I/O performanceComplexity of transformation logic
  • Ignoring performance tests before cutover.
  • Incomplete data migration due to missing transformation rules.
  • No monitoring after migration; issues remain undetected.
  • Underestimating hidden dependencies like stored procedures.
  • Overestimating compatibility between engines.
  • Failing to consider transaction sizes and locking.
Database administration and SQL expertiseData modeling and ETL/transformationRelease and deployment coordination
Data consistency and integrityAvailability requirements and allowed downtimeCompatibility between source and target platform
  • • Proprietary features of the source system
  • • Time constraints of maintenance windows
  • • Regulatory requirements for data movement