Legacy Database Migration to PostgreSQL

[Serge Pilko 0]

Turning a legacy database into a modern, high-performance platform might seem intimidating. Old routines, custom PL/SQL, proprietary extensions. There is a lot that can break. But with careful planning, the right tools, and a methodical approach, you can make the move safely. 

Migration can take 3 phases:

1. Assessment phase. The first step is identifying the schema's complexity, custom code, and potential pitfalls.
2. Pilot phase. The second step is about testing the migration path with low-risk components first. 
3. Full migration phase. The third step is to minimize downtime and ensure that your data is consistent. You should prepare a rollback plan, backup your data, and carefully cut over with extensive testing afterwards.

 

Some of the most common pitfalls you may face include:

• Fully trusting automation to do everything.
• ORM differences. 
• Transaction isolation and locking mechanisms. It is not the same in Oracle and PostgreSQL.
• Extension dependencies. Missing libraries can break your migration if you are not careful.

 

Our team at Softacom recently successfully performed a complex migration for a financial institution. It required a phased approach. We migrated over 800 tables and 300 routines from Oracle to PostgreSQL, retaining data integrity and functionality, all while avoiding significant outages and preserving business operations.  

 

If you want more detailed information about what we did, you can find it here: https://www.softacom.com/wiki/how-to-migrate-a-legacy-system-to-postgresql-real-world-example/