Most modern businesses today make use of a wide variety of databases and Data Warehouses to run their day-to-day operations. Companies feel the need to use multiple databases because there is no single database that can fulfill all their operational and analytical requirements. Two of the most widely used databases are Oracle and PostgreSQL.

Oracle is used by businesses to run their operations, and PostgreSQL is primarily used for analytical purposes. This article will provide you with a comprehensive understanding of how you can set up Oracle to PostgreSQL Migration to analyze the operational data of your business seamlessly.

What is the Need for Oracle to PostgreSQL Migration?

Oracle and PostgreSQL are two well-known Enterprise-grade databases. While Oracle is available as a License-based Model, PostgreSQL is a completely free and open-source offering. Oracle’s Enterprise-grade support and service ecosystem make it the preferred in use cases where high availability and security are a concern.

It can be used as a transactional database or as a Data Warehouse. This is not to say that PostgreSQL lacks availability or security. Being an open-source offering, premium-grade enterprise support is lacking in the case of PostgreSQL. Featurewise, PostgreSQL boasts almost all the features that Oracle has. Its open-source nature means, there is big support from the community and there is no dearth of plugins and extensions for PostgreSQL.

Since Oracle and PostgreSQL are offered based on different pricing models, many organizations tend to use both in some way or the other to optimize costs.

Oracle being the one with paid Enterprise support tends to be used for mission-critical workloads whereas PostgreSQL is usually a good choice for analytical workloads. The problem with this approach is that the data tends to be on different platforms making it difficult for analysts to work. This is why businesses feel the need to set up Oracle to PostgreSQL Migration so that a suitable platform can be used based on the use case.

Related: If you’re looking to migrate your data from Oracle to MongoDB, discover our comprehensive guide on Oracle to MongoDB replication. Additionally, explore RDS Oracle PostgreSQL integration to learn efficient ways to integrate Oracle and PostgreSQL in your database environment.

6 Simple Stages to Oracle to PostgreSQL Migration 

The process of Oracle to PostgreSQL Migration consists of many stages that include managing indexes, structured and unstructured data, and stored manuals. The following steps explaining the different stages for Oracle to PostgreSQL Migration are listed below.

1) Basic Preparation 

It is essential to let your team know about the transition from Oracle to PostgreSQL Migration. Preparing the team and equipping them with required technical knowledge and educating them with the benefits of PostgreSQL and usage for collaboration, data governance, and seamless business continuity.

2) Assessment of the Environment 

Many times companies decide to fasten the Oracle to PostgreSQL Migration and shift all the critical modules of the application ignoring checking the compatibility, and capabilities, and assessing the environment. 

For smooth Database Migration, one should first stop using third-party applications offered by Oracle Database because they will not support the alternatives for open source. Also, try to analyze the number of functions that you want to migrate from the Database and which needs any update or correction to stay compatible with the new Database.

3) Planning and Solutions

This is a very critical phase of Oracle to PostgreSQL Migration because many strategies are discussed, and decisions need to be finalized. Companies should take into consideration all the possible conflicts that may arise and find solutions for them to avoid any risks later. 

Companies should have detailed plans for deployment options of PostgreSQL, bandwidth requirements, Data Migration strategies, and data transfer. Also, keep in mind that there should be minimal downtime as possible. 

4) Picking the Suitable Tool

Manually indulging in the Oracle to PostgreSQL Migration can be a tedious job if it consists of many Databases and complex data. Leveraging automation tools will significantly cut off the time to complete the task and helps in maintaining the Database after deployment.

5) Migration process

With the help of specialized tools, you are able to connect to Oracle Database so that you can scan and extract the structured data from Oracle Database and generate scripts from it. These scripts can then be fed to PostgreSQL. This Oracle to PostgreSQL Migration process involves the execution of tasks, schema migration, SQL migration, and identifying functions equivalent to Oracle.

  • Schema Migration: It enables users to create many independent schemas without the need for separate users and create objects in them. 
  • Functional Testing: After successful schema conversion and performing Oracle to PostgreSQL Migration, it is required to do functional testing on it. You can also test the schema in both Databases and compare the results for similarities.
  • Performance Testing: The transactions and features of Oracle and PostgreSQL are different that require performing performance testing so that the differences can be tracked, locked, and fixed.
  • Data Migration: With the help of the right tool and strategy used to perform Data Migration can solve and avoid many challenges.

6) Expect Business Effects

You need to make sure that Oracle to PostgreSQL Migration process doesn’t disrupt the business activities hence minimizing the time in migrating the data. Also, it is essential to estimate the downtime tolerance during migration and track the operational changes after integrating PostgreSQL with other applications, features, etc.

What are the Methods to Set up Oracle to PostgreSQL Migration?

The two methods that can be used to set up Oracle to PostgreSQL Migration are as follows:

Method 1: Manual Oracle to PostgreSQL Migration

The following steps can be implemented to manually set up Oracle to PostgreSQL Migration:

Step 1: The first step is to install the PostgreSQL ODBC driver in the system in which Oracle is installed.  In Linux, you can do this by executing the following command:

yum install postgresql93-odbc

The command will differ according to the flavor of your Linux. 

Create a file named odbc.ini and place it in your user folder. This file should contain the details of the target PostgreSQL database.

[ODBC Data Sources]
  Debug = 1
  CommLog = 1
  ReadOnly = no
  Driver = /usr/pgsql-9.3/lib/
  Servername = <PostgreSQL_SERVER_IP>
  FetchBufferSize = 99
  Username = pg_user
  Password = pg_pass
  Port = 5432
  Database = pgdb
  Driver = /usr/lib64/

Step 2: You will now configure the heterogeneous services in Oracle. For this, you need to create three files with the extension .ora. You will begin by creating the first while which initializes the heterogeneous services. Navigate to /hs/admin in your Oracle installation directory and create a file named initdblink.ora with the following content:


The important section is the part where you need to mention the ODBC information for the destination PostgreSQL installation. Ensure that you specify the same name in HS_FDS_CONNECT_INFO.

Step 3: The next step is to modify a file located in the /network/admin directory of your Oracle installation. Find the file tnsnames.ora and add details about the destination PostgreSQL instance.


Step 4: Locate the listener.ora file in the same directory and add the following details:


Oracle listeners are responsible for listening for connections to other databases and handling them appropriately. The name of the configured listener can be found out from the listener.ora file. After changing the file, execute the below command to restart the listener.

lsnrctl reload <your_LISTENER_NAME>

Step 5: The final step is to start PostgreSQL and type the following statement to establish the connection:

Create database link TARGET_PG_LINK connect to "pg_user" identified by "pg_pass" using ‘TARGET_PG_LINK’;

If everything went well, you should now be able to execute queries in PostgreSQL like the one below.

select * from "target_table_name"@TARGET_PG_LINK;

What are the Limitations of Manual Oracle to PostgreSQL Migration?

The limitations of manually setting up Oracle to PostgreSQL Migration are as follows:

  • Even though the user only has to make a few configuration changes in order to set up Oracle to PostgreSQL Migration, it is difficult to get this integration right without deep Oracle administration knowledge. This might lead to Oracle throwing errors because of multiple configuration parameters that vary across different versions.
  • Even after getting the Oracle to PostgreSQL Migration right, the connection, in reality, has many constraints and rough edges with respect to the SQL queries that can be executed. You will run across problems with functions and data types that are not supported at source and target databases.
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Method 2: Using Hevo to Set up Oracle to PostgreSQL Migration

Oracle to PostgreSQL Migration: Hevo Logo | Hevo Data

Hevo helps you directly transfer data from Oracle and various other sources to PostgreSQL, Business Intelligence tools, Data Warehouses, or a destination of your choice in a completely hassle-free & automated manner.

Hevo is fully managed and completely automates the process of not only loading data from your desired source but also enriching the data and transforming it into an analysis-ready form without having to write a single line of code. Its fault-tolerant architecture ensures that the data is handled in a secure, consistent manner with zero data loss.

Hevo takes care of all your data preprocessing needs required to set up Oracle to PostgreSQL Migration and lets you focus on key business activities and draw a much more powerful insight on how to generate more leads, retain customers, and take your business to new heights of profitability. It provides a consistent & reliable solution to manage data in real-time and always has analysis-ready data in your desired destination. 

The following steps can be implemented to set up Oracle to PostgreSQL Migration using Hevo:

  • Configure Source: Connect Hevo Data with Oracle by providing a unique name for your Pipeline along with information about your Oracle database such as its name, IP Address, Port Number, Username, Password, etc.
Oracle to PostgreSQL Migration: Oracle Hevo Source | Hevo Data
Image Source: Hevo Docs
  • Integrate Data: Complete Oracle to PostgreSQL Migration by providing your PostgreSQL database credentials such as your authorized Username and Password, along with information about your Host IP Address and Port Number value. You will also need to provide a name for your database and a unique name for this destination.
Oracle to PostgreSQL Migration: PostgreSQL Hevo Destination | Hevo Data
Image Source: Hevo Docs

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This article provided you with a step-by-step guide on how you can set up Oracle to PostgreSQL Migration manually or using Hevo. However, there are certain limitations associated with the manual method. If those limitations are not a concern to your operations, then using it is the best option but if it is, then you should consider using automated Data Integration platforms like Hevo.

Hevo helps you directly transfer data from a source of your choice to a Data Warehouse, Business Intelligence, or desired destination in a fully automated and secure manner without having to write the code. It will make your life easier and make data migration hassle-free. It is User-Friendly, Reliable, and Secure.

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