Setting up Oracle to PostgreSQL Migration: 2 Easy Methods

on Data Analytics, Data Integration, Database Management Systems, ETL • May 11th, 2021 • Write for Hevo

Oracle to PostgreSQL Migration | Hevo Data

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.

Table of Contents

What is Oracle?

Oracle is a Relational Database Management System (RDBMS) from Oracle Corporation. Oracle’s Relational Database Management System (RDBMS) is a multi-model system, that was primarily designed for Data Warehousing and Enterprise Grid Computing. It is now the database of choice for almost all Enterprises due to its cost-effective solution for data management. Oracle houses support for Structured Query Language (SQL), allowing users to easily interact with the database.

Oracle offers five different editions of its RDBMS from which users can choose based on their business and data requirements. These editions are as follows:

  • Express Edition: This is an entry-level edition that is available free of cost for everyone to download, install, manage, develop, deploy, etc.
  • Standard Edition One: This edition is considered to be suitable for business applications that require a single-server or are highly branched but require limited features.
  • Standard Edition: In addition to all features in Standard Edition One, the Standard Edition houses support for Oracle Real Application Clustering Service and larger machines.
  • Enterprise Edition: The Enterprise Edition offers numerous advanced features such as improved performance, advanced security, availability, and scalability. These features are required for most critical applications and business processes in which online transaction processing is involved.
  • Personal Edition: Except for Oracle Real Application Clustering, the Personal Edition houses all features of the Enterprise Edition.

More information on Oracle can be found here.

What are the Key Features of Oracle?

The key features of Oracle are as follows:

  • Client/Server Architecture: Oracle is based on Distributed Systems that have the same degree of data consistency and transparency as any non-distributed Systems along with all advantages of a local Database Management System. Oracle takes full advantage of this distributed architecture by implementing a Client/Server Model. Hence, Oracle allows processing to be split into Client and Server application programs.
  • Portability: Oracle can easily be ported to work on a wide variety of Operating Systems. Hence, any application developed using Oracle can be ported to any other Operating System as per requirements without making any changes to it.
  • Scalability and Performance: Oracle houses numerous features like advanced Portability and Real Application Clustering that make it highly scalable. It also gives users the ability to tune the performance of their database as per requirements, allowing it to retrieve and alter data faster, thereby improving query execution time along with application operations.
  • Availability: All real-time applications now require high Data Availability. Since Oracle is built on high-performing computing environments, it can be configured easily to ensure all-time Data Availability. This ensures that the data is accessible during planned, unplanned failures or downtimes.
  • Backup and Recovery: Oracle houses robust recovery features that enable users to recover data from almost all kinds of database failures. In case of a failure, the database is recovered in no time, thereby ensuring high availability. Also, the unaffected parts of the database are still available even while the affected ones are getting recovered.
  • Security: Oracle is considered to be the database of choice for most Enterprises and hence, stores a lot of sensitive information. The security of this data is always the top priority for obvious reasons. Oracle houses advanced in-built mechanisms that can be used to control and monitor data access and usage. It can be used to implement strong authorization policies that can help prevent unauthorized access to the data and only allow distinct access to the users as per requirements.
  • Database Integrity: Oracle can ensure the consistency of all the data stored by enforcing Data Integrity. This saves a lot of engineering resources that would have been otherwise utilized in managing integrity checks.
  • Concurrent Processing: Oracle allows a large number of users to execute a variety of applications concurrently.

What is PostgreSQL?

PostgreSQL is a free and Open-source database. It is now considered to be one of the most powerful Relational Database Management Systems available in the market. It incorporates SQL and adds a set of new features that allow PostgreSQL to be used for Transactional Databases and as a Data Warehouse for analytical purposes. 

One of the most significant advantages of using PostgreSQL and why it’s becoming the preferred choice for most businesses using Relational Databases is its ability to support the Object Relational Model, allowing users to define custom data types depending on the use case in their application.

More information on PostgreSQL can be found here.

What are the Key Features of PostgreSQL?

The key features of PostgreSQL are as follows:

  • Data Integrity: PostgreSQL ensures Data Integrity by giving users the ability to create Primary and Foreign Keys, Unique and Not Null constraints, Explicit and Advisory Locks, Exclusion Constraints, etc.
  • Multiple Data Types: PostgreSQL houses support for a wide variety of data types, including Primitive data types such as Integer, String, Boolean, etc., Structured data types such as an array, date, time, etc., and Documents such as XML, JSON, etc.
  • Highly extensible: PostgreSQL is considered highly extensible due to its support for various Procedural Languages such as PL/pgSQL, Perl, Python, etc. along with JSON/SQL Path Expressions, and Foreign Data Wrappers that can be leveraged to connect to different databases with a standard SQL interface.
  • Robust Security: PostgreSQL houses a robust Access Control System along with several secure authentications, including Lightweight Directory Access Protocol(LDAP), SCRAM-SHA-256, etc., making it one of the most secure Relational Database Management Systems (RDBMS) available.
  • Highly Reliable: PostgreSQL provides several disaster recovery techniques such as Active Standbys, Point In Time Recovery (PITR), and Tablespaces, along with numerous types of Replications such as Logical, Synchronous, and Asynchronous.

What are the PostgreSQL advantages over Oracle Database?

Compare PostgreSQL vs. Oracle

Some of the key areas of advantages of PostgreSQL over Oracle Database are listed below:

  • Application programming
  • Authentication
  • Extensibility
  • Languages
  • Localization
  • Performance
  • Scalability

PostgreSQL vs. Oracle: Application Programming 

PostgreSQL and Oracle both provide API support for developing applications and efficiently communicating with the Databases. But PostgreSQL offers more flexible APIs as it is an open-source Database allowing communities to develop extended versions of API and help developers access any component of PostgreSQL just by adding the header file to the projects.

PostgreSQL vs. Oracle: Authentication 

Oracle offers its built-in authentication system to its users developed by Oracle. PostgreSQL depends on host-based authentication which allows it to support a wide range of authentication methods that adds flexibility for authentication.

PostgreSQL vs. Oracle: Extensibility

Most of the proprietary plugins are offered by Oracle, whereas PostgreSQL offers many plugins developed by community support.

PostgreSQL vs. Oracle: Languages

Oracle has its built-in programming language called PL/SQL. While PostgreSQL, along with PL/SQL language support, also comes with many other language support. Moreover, PostgreSQL allows users to create additional procedural languages using its extension system.

PostgreSQL vs. Oracle: Localization

Oracle Database comes with a globalization Development kit with globalization support tools and Unicode character support. While the localization system services of the PostgreSQL are developed to deliver automatic character encoding and collation support.

PostgreSQL vs. Oracle: Performance

You can add an unlimited number of nodes in a read cluster so that you can tune it differently Adding a new node to Oracle Database has an additional cost, whereas, in PostgreSQL, you can also add any number of nodes to increase the performance of reading the data. The cost of any particular read operations in PostgreSQL can be reduced to nothing but not in Oracle.

PostgreSQL vs. Oracle: Scalability

Oracle supports vertical read scalability while PostgreSQL can create virtually any number of nodes in a read cluster that is dependent on the resources available to dedicate to it.

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 of 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 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.

Ways to Set up Oracle to PostgreSQL Migration

Method 1: Manual Oracle to PostgreSQL Migration

This method involves manually configuring the PostgreSQL ODBC driver to set up Oracle to PostgreSQL Migration.

Method 2: Using Hevo to Set up Oracle to PostgreSQL Migration

Hevo provides a hassle-free solution and helps you directly transfer data from Oracle to PostgreSQL without any intervention in an effortless 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. Hevo’s pre-built integration with Oracle, PostgreSQL along with 100+ Sources (including 30+ free Data Sources) will take full charge of the data transfer process, allowing you to set up Oracle to PostgreSQL Migration seamlessly and focus solely on key business activities. 

Get started with Hevo today! Sign up for the 14-day free trial!

6 Simple Steps 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 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 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 Solutioning

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 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]
  TARGET_PG_LINK = PostgreSQL
[TARGET_PG_LINK]
  Debug = 1
  CommLog = 1
  ReadOnly = no
  Driver = /usr/pgsql-9.3/lib/psqlodbc.so
  Servername = <PostgreSQL_SERVER_IP>
  FetchBufferSize = 99
  Username = pg_user
  Password = pg_pass
  Port = 5432
  Database = pgdb
[Default]
  Driver = /usr/lib64/liboplodbcS.so.1

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:

 HS_FDS_CONNECT_INFO = TARGET_PG_LINK
 HS_FDS_TRACE_LEVEL = 0
 HS_FDS_SHAREABLE_NAME=/usr/pgsql-9.3/lib/psqlodbc.so
 set ODBCINI=/PATH_TO_ODBC_FILE/.odbc.ini

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.

TARGET_PG_LINK  =
  (DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=<ORACLE_HOSTNAME>)(PORT=<ORACLE_PORT>))
	(CONNECT_DATA=(SID=TARGET_PG_LINK))
	(HS=OK)
  )

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

SID_LIST_<your_LISTENER_NAME>=
  (SID_LIST=
  	(SID_DESC=
     	(SID_NAME=TARGET_PG_LINK)
     	(ORACLE_HOME=<ORACLE_HOME_DIRECTORY>)
     	(PROGRAM=dg4odbc)
  	)
  )

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.

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 have 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
  • 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

Check out what makes Hevo amazing:

  • Real-Time Data Transfer: Hevo with its strong Integration with 100+ Sources (including 30+ Free Sources), allows you to transfer data quickly & efficiently. This ensures efficient utilization of bandwidth on both ends.
  • Data Transformation: It provides a simple interface to perfect, modify, and enrich the data you want to transfer. 
  • Secure: Hevo has a fault-tolerant architecture that ensures that the data is handled in a secure, consistent manner with zero data loss.
  • Tremendous Connector Availability: Hevo houses a large variety of connectors and lets you bring in data from numerous Marketing & SaaS applications, databases, etc. such as HubSpot, Marketo, MongoDB, Oracle, Salesforce, Redshift, etc. in an integrated and analysis-ready form.
  • Simplicity: Using Hevo is easy and intuitive, ensuring that your data is exported in just a few clicks. 
  • Completely Managed Platform: Hevo is fully managed. You need not invest time and effort to maintain or monitor the infrastructure involved in executing codes.
  • Live Support: The Hevo team is available round the clock to extend exceptional support to its customers through chat, email, and support calls.

Conclusion

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.

Details on Hevo’s pricing can be found here. Give Hevo a try by signing up for the 14-day free trial today.

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