Oracle to PostgreSQL SQL Conversion Guide: Real-World Examples for DBAs
We had 847 stored procedures written in Oracle PL/SQL. The CTO announced we were moving to PostgreSQL to cut licensing costs by $200,000 annually. The migration deadline was three months away.
I spent the first week manually converting procedures. At that pace, I'd finish in 18 months. That's when I realized: most Oracle-to-PostgreSQL conversions follow predictable patterns. Once you know these patterns, conversion becomes systematic, not guesswork.
Oracle to PostgreSQL migration isn't about rewriting everything from scratch. 70-80% of SQL works with minor syntax adjustments. The remaining 20-30% requires understanding key differences in how each database handles data types, functions, and procedural logic.
This guide covers real production SQL conversions from Oracle to PostgreSQL. If you're an Oracle DBA planning a PostgreSQL migration, these are the patterns, gotchas, and solutions that actually work.