With its mature architecture, strong community and proven enterprise-scale performance, PostgreSQL has become a serious alternative to Oracle. Yet a successful migration is far more than copying data from one database to another.
1. Inventory and compatibility analysis
The first step is to extract schemas, PL/SQL packages, triggers, scheduled jobs and SQL usage on the application side. This inventory shows which objects can be converted automatically and which must be rewritten by hand.
2. Data types and PL/SQL conversion
Choosing the wrong PostgreSQL equivalents for types such as NUMBER, DATE and VARCHAR2 affects both performance and data integrity. When moving PL/SQL packages to PL/pgSQL, differences such as package variables, autonomous transactions and error handling need careful attention.
3. Performance and testing
The query planners of the two databases behave differently. Critical queries should be tested with realistic data volumes, the indexing strategy re-evaluated and PostgreSQL-specific maintenance such as VACUUM and autovacuum planned from the start.
4. A zero-downtime cut-over plan
For large systems, data synchronization, a parallel-run period and a rollback plan significantly reduce risk. At Valueset we manage migration projects end to end — from analysis to go-live and post-migration performance monitoring.