Migrate from MySQL to PostgreSQL

Why Migrate

• Advanced Data Types: PostgreSQL natively supports JSON/JSONB, arrays, hstore, range types, and custom types — enabling richer data models without workarounds.
• Superior Concurrency: PostgreSQL's MVCC implementation handles concurrent reads and writes without table-level locking, delivering better performance under heavy load.
• Standards Compliance: PostgreSQL adheres more closely to SQL standards, making your queries more portable and your application less dependent on vendor-specific syntax.

Migration Roadmap

1. Schema & Query Audit (1–2 weeks): Analyze MySQL schemas, stored procedures, triggers, and application queries. Identify MySQL-specific syntax that needs PostgreSQL equivalents.
   • Schema compatibility report
   • Query migration guide
   • Data type mapping document
2. Schema Migration & Data Transfer (2–4 weeks): Convert schemas to PostgreSQL, migrate data using pgLoader or AWS DMS, and update application queries and ORM configurations.
   • PostgreSQL schema with indexes and constraints
   • Complete data migration with validation
   • Updated application data access layer
3. Testing & Switchover (1–2 weeks): Run integration tests against PostgreSQL, validate data integrity with checksums, and perform the production cutover.
   • Data integrity validation report
   • Performance benchmark comparison
   • Production switchover with rollback plan

Risks & Mitigation

• MySQL-specific SQL syntax breaks on PostgreSQL: We audit every query and stored procedure during the planning phase, converting MySQL-specific syntax like LIMIT/OFFSET, backtick quoting, and auto_increment.
• Data type mismatches cause data loss: We create a comprehensive data type mapping and run row-count and checksum validation after every data transfer to ensure zero data loss.

Estimated Scope

Hours: 60–120 | Cost: $120–$240 | Timeline: 4–8 weeks

Frequently Asked Questions

Will our ORM (Sequelize, Prisma, TypeORM) work with PostgreSQL?

Yes. All major ORMs support PostgreSQL with minimal configuration changes. We update the connection string, dialect, and any MySQL-specific query overrides.

How do you handle stored procedures and triggers?

We rewrite MySQL stored procedures in PL/pgSQL, PostgreSQL's procedural language. Triggers are converted to PostgreSQL trigger functions with equivalent behavior.

Can we run MySQL and PostgreSQL in parallel during migration?

Yes. We set up continuous replication from MySQL to PostgreSQL using tools like pgLoader or Debezium so both databases stay in sync until cutover.