Oracle and PostgreSQL are two different platforms with varying characteristics when it comes to handling your databases. It is not uncommon to see users migrate their definitions, data, and stored procedures from one platform to another. Most users migrate from Oracle to PostgreSQL for cost, flexibility, and customizability reasons, among others. Are you planning to migrate your databases soon? Here is the complete Oracle to PostgreSQL migration guide in summary:

Step 1: Assessment

The very first step to take in the migration of databases is complete assessment. There are several steps to take, and each is important to ensure a smooth migration. The first step is to analyze how easy it will be to migrate. This initial assessment should be followed by compatibility assessment, application code assessment, and architecture assessment and cleanup.

Step 2: Schema Migration

Schema conversion and migration is the next step, and it should be handled carefully to ensure the success of the migration. Schema is also known as a ‘User’ in Oracle, where every user will have their own schema. In PostgreSQL, a schema must be explicitly specified, or new objects will be automatically sent to the public schema. This phase of the migration can be accomplished with reliable schema migration tools. Some tools you can get for free are Ora2pg, Ora_migrator, Orafce, and EDB Migration Portal. There are commercial conversion tools you can also use, like Amazon’s AWS Schema Conversion Tool, which works very well.

Step 3: Functional Testing

This is an important step that will let you know if everything is going smoothly. It involves testing the converted schema on a sample dataset. The most effective way to do this is to load some sample data from a source database development or testing environment into PostgreSQL. You can then proceed by using appropriate data access drivers to set up an application connection. You should allow the connected application to do full functional testing on the converted objects with DMLs. This will be most effective when you load the same dataset in Oracle and PostgreSQL to see if they yield identical results. Depending on the results from the testing, you can move to the next step or address any encountered issues.

Step 4: Performance Testing

This step will detect loopholes in the process and fix them before the migration process is completed. Since the features and functionalities of both platforms differ, some slight differences will be revealed by the applications, and this is the phase they will be captured and fixed.

Step 5: Data Migration

This is the final stage of the migration process. It is at this point that you can migrate data from Oracle to PostgreSQL, and there are different tools you can use for this process. According to how they work, data migration strategies are categorized into Snapshot, Snapshot in Parallel, or Change Data Capture (Replication).


Oracle and PostgreSQL are among the go-to options used by businesses for their database management. Factors such as cost-saving, flexibility, and customization options may prompt you to migrate from Oracle to PostgreSQL. Hopefully, our migration from Oracle to PostgreSQL tutorial will be of great help to you when switching between platforms.