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PostgreSQL vs. Oracle: Let’s Compare

Author: Vijay Muthu | | March 30, 2021

Companies are faced with many options when deciding on a database management system. Discover the key differences between PostgreSQL vs. Oracle that will help you make an informed decision.

Types of Database Management Systems

Database management systems can be categorized as open-sourced or closed-source systems. Open-source means that anyone can download and modify the source code of the database technology for free. Closed-source means that the source code is private and inaccessible to everyone except the developers and authorized parties. You often need to pay a license fee to use closed-source software.

Open-sourced software has an active community of users and developers who can check the code for bugs, extend the software’s functionality, and often provide support for the solution. You have greater flexibility with open-sourced software, as you can customize it based on your company’s needs and have access to a large community for development resources.

Closed-source software offers less flexibility compared to open-source solutions, but it can make up for that through premium support options on-hand for emergencies, extensive training, and documentation resources, enterprise-grade security and stability, and less decision-making on the software versions to implement.

You can also find overlap between closed-source and open-source capabilities. For example, closed-source software may provide an add-on framework that allows third-party developers to extend functionality, while some open-source software can provide access to paid support solutions.

Key Differences Between PostgreSQL and Oracle

When you look at PostgreSQL vs. Oracle database management systems, the main difference between these two databases is that PostgreSQL is an open-source database, while Oracle is a closed database system. PostgreSQL is a free relational object-oriented database management system that is developed by volunteer developers worldwide. Oracle is a licensed commercial relational database management system.

Both database systems use similar concepts such as schemas, tablespaces and indices, but they diverge in areas such as replication and support. Let’s explore the ways that these two database systems handle vital operations.



  • High availability
  • Four levels of transactions: Read Uncommitted, Read Committed, Repeatable Read, Serializable
  • ACID-compliant



  • High availability
  • Higher transactions per second
  • More functional than PostgreSQL, but these functions come at a price premium
  • ACID-compliant



  • More scalable due to its open-source characteristics
  • Databases accommodate any volume of data
  • Cluster-based storage solutions allow for free expansion
  • Foster integrity during scalability operations with WAL files, although these files are limited to 16 MB



  • Have to spend more on infrastructure to carry out scalability operations, as the Standard edition only has four sockets, while the Enterprise edition offers more
  • Maintain data integrity with redo logs



  • Offers roles and inherited roles that allow developers to set permissions
  • Supports native SSL that assists in encrypting server communications
  • Provides extra access controls through SE-PostgreSQL that rely on SELinux’s security policy



  • More robust security features than PostgreSQL
  • Higher cost editions are required to access advanced security options
  • Resilient through security assessments, data protection, auditing, and monitoring
  • Provides excellent isolation solutions between pluggable databases and independent key encryption management



  • Active community that offers free online support via blogs, emails, code, and other channels
  • No phone number to call for emergencies
  • The cost to hire PostgreSQL community developers for premium support is less than a comparable Oracle specialist
  • Third-party support providers are also available, such as EnterpriseDB and 2nd Quadrant, that also offer their own PostgreSQL distribution



  • Expensive support
  • Large corporations have to hire Oracle consultants or depend on Oracle’s support, with a cost of up to 25 percent of the license fees
  • Emergency support is available by phone

Compatibility & Replication


  • High availability through Streaming Replication
  • Master-slave replication provides developers with flawless performance during backup, task allocation, and clustering
  • ORM framework support
  • Support for a larger group of APIs than Oracle, making it more compatible  with many applications, add-ons, and SQL environments
  • JDBC, ODBC, OLEDB and .Net library support



  • High availability through DataGuard
  • Master-slave replication provides developers with flawless performance during backup, task allocation, and clustering
  • Master-master replication
  • ORM framework support
  • JDBC, ODBC, OLEDB and .Net library support
  • Less API support than PostgreSQL

SQL Compliance


  • Less complex SQL Syntax, as PostgreSQL follows standard SQL
  • Non-standard built-in procedural extensions are available through pg/SQL
  • Pg/SQL is a less mature technology than Oracle’s, and is slower
  • Developers can use query handlers such as R and Python to write directly into the database



  • More complex SQL Syntax compared to PostgreSQL, as this database follows Oraclism
  • Non-standard built-in procedural extensions are available through PL/SQL
  • PL/SQL is a faster technology than pg/SQL

High Availability


  • PgPool in PostgreSQL Enterprise edition provides similar functionality to Oracle Real Application Clusters
  • Add nodes dynamically through horizontal scalability options
  • PgPool is not a built-in feature to PostgreSQL and requires many Clusterware tools to achieve similar functionality to Real Application Clusters



  • Databases can be shared across a pool of servers through Oracle Real Application Clusters
  • When one instance of failure occurs, the database can run on the remaining databases to offer continuous workflow management
  • Real Application Cluster is a built-in feature

Migration Tools


  • Offers many tools that support migration from Oracle
  • Ora2PG migrates large projects
  • Oracle_FDW moves schemas and data
  • Orafce ensures function compatibility
  • PGREPLAY is a stress testing tool that can be hacked to stress test large databases
  • For migrating code, third-party tools such as the AWS Schema Conversion Tool work well
  • Moving huge Oracle databases to PostgreSQL can consume significant resources and time



  • Database Replay and SQL Performance Analyzer in Real Application Testing allow you to analyze and test migration requirements before the move
  • The migration process is easier to plan through these preparation tools, reducing the time and resources required compared to PostgreSQL

Backup and Recovery


  • The data recovery process is straightforward, as it simply replaces directories and sub-directories plus the associated WAL files
  • PGdump and pgbasebackup are simple and straightforward database backup solutions



  • The data recovery processes can be overly complex
  • RMAN provides an efficient and straightforward database backup

Choosing a Database Management System

Overall, PostgreSQL and Oracle are evenly matched in their capabilities, performance, and compatibility. Oracle takes the lead on security, replication, and availability, while PostgreSQL has stronger API compatibility, cheaper support and more robust scalability. As database administrators, we think your choice of databases depends on your company’s priorities.

If you want an easy-to-use database you can customize for your operations, with a low Total Cost of Ownership, then PostgreSQL is a good choice. If high availability and flawless replication during voluminous transactions are the most important things for your business, then Oracle provides robust functionality.

Datavail offers many resources to help you decide between PostgreSQL and Oracle, from choosing the right database technology for your company to executing a migration. We deliver the DBA expertise, services and strategies to help you get the most out of your data and database technology.

Your database administration team manages and optimizes your databases through monitoring, maintenance, disaster recovery, user support, training, migration planning, and more. We offer flexible DBA capacity, so you get the right level of support throughout your technology journey, from one-time projects to 24/7 assistance.

See how Datavail can help you manage all your complex database needs and maximize your investment in PostgreSQL, Oracle and other database technologies.

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