
A Strategic Guide to Cost Avoidance, Workload Offloading, and Licensing Reduction
For organisations running Oracle Databases — whether on-premise or in the cloud — licensing cost is one of the most significant and persistent line items in the technology budget. Oracle's processor-based licensing model means that every reporting query, every integration call, and every analytical dashboard run against the Oracle database is consuming licensed compute capacity. As user numbers grow and data volumes expand, the instinct is to buy more Oracle processors — and with each processor costing tens of thousands of dollars in perpetual license fees plus 22% annual support, the financial trajectory is steep.
This article presents a proven, practical strategy that breaks that cycle: the offloading of read-only and analytical workloads from Oracle to PostgreSQL via real-time data replication, using Quest SharePlex as the replication engine, Pebble IT's Osprey tool to intelligently design and orchestrate the replication queues, and PostgreSQL as the unlimited, license-free destination platform (if Community Edition is used, else a PostgresPURE license that is typically 90%+ less than equivalent Oracle licensing for Enterprise compliance and support).
The outcome is twofold. First, it delivers immediate and ongoing cost avoidance — the most valuable kind of saving because it prevents expenditure that would otherwise be unavoidable. Second, it creates the architectural foundation for a broader Oracle Optimisation strategy that can progressively reduce the Oracle processor footprint over time, generating genuine and measurable cost reduction.
Cost avoidance is just as valuable as cost reduction. Preventing the need to purchase additional Oracle processors as your user base grows is money that never leaves the organisation.
Oracle Database Enterprise Edition is the core database for many organisation's most critical systems. It is powerful, mature, and deeply embedded in enterprise and government architectures. It is also expensive — and the cost structure is designed in ways that penalise growth.
Oracle licenses its database software on a per-processor basis. Each physical CPU core on a server running Oracle must be counted, multiplied by a core factor (typically 0.5 for Intel & AMD x86 processors), and the result rounded up to determine the number of processor licenses required. At the current list price of US$47,500 per processor license for Enterprise Edition, a typical dual-socket server with 16 cores per socket requires 16 processor licenses — a list price commitment of US$757,000. That is without Diagnostics & Tuning, Advanced Security (encryption) or Partitioning. Those options would add another 60% on to the price. This is why virtualisation is so important, and Oracle is very restrictive in this regard only honouring a single solution on most operating systems. The popular choice of VMWARE, Hyper-V and Nutanix is not a license compliant choice and has led to many problems between clients and Oracle Corp.
On top of this, annual support — Oracle's software update and support subscription — runs at 22% of the license cost per year. In the example above, that is approximately US$166,000 every year, regardless of how heavily the system is used. With annual increases of 10% per year, a 5-Year cost of this example is US$1.13M over 5-Years bringing the total cost to US$1.77M – no wonder Australian organisations are screaming out for alternatives.
The critical problem is not just the baseline cost — it is the growth model. When an organisation's Oracle database becomes a bottleneck due to increased reporting load, more integration queries, or a growing user population running ad-hoc analysis, the conventional response is to scale up the Oracle hardware: more CPU cores, more processor licenses, more annual support fees.
More recently, the worldwide trend is to add more integration, more use of your data, and more intelligent querying of your data, particularly by AI tools and agents. The pressure trend is upwards.
This creates what is effectively a licensing trap. Every new business intelligence project, every new integration, every new analytical use case that touches Oracle data adds compute demand that, at scale, becomes a licensing cost event. Many organisations have found themselves acquiring Oracle licenses not to support new transactional workloads, but simply to support the reporting and integration traffic that surrounds their existing workloads.
A growing reporting user base should never trigger an Oracle processor purchase. PostgreSQL eliminates this coupling entirely — add as many reporting users, BI tools, and integrations as needed, on hardware of any scale, at no/little additional license cost.
Beyond the Headline License Fee
The true cost of Oracle extends well beyond the processor license price. Technology leaders evaluating Oracle optimisation strategies should account for:
The most impactful near-term step in an Oracle Optimisation strategy is not migration — it is offloading. Rather than moving Oracle workloads to PostgreSQL immediately (which requires application changes and careful planning), the offloading approach keeps Oracle exactly where it is and redirects the read-only workload — reporting queries, analytics, BI tool access, integration reads — to a PostgreSQL replica that is synchronised in real-time.
This is not a compromise solution. It is a deliberate architectural choice that delivers significant financial benefit immediately, creates a foundation for future migration, and carries very low risk because Oracle remains fully operational throughout.
The architecture is straightforward:
The result: Oracle's processor capacity is freed from read-only workloads. Those workloads move to PostgreSQL servers that can be as large as required — 64 cores, 512 GB of RAM, multiple nodes — without any additional licensing cost*.
The following table illustrates the types of workloads that belong on PostgreSQL rather than Oracle in an optimised architecture:
Each row in this table represents a category of compute demand that currently drives Oracle processor utilisation. Moving these workloads to PostgreSQL does not just save money on the next license renewal — it prevents the purchase of future licenses as those workloads grow.
Quest SharePlex is the replication engine at the heart of this strategy. It has been used in Oracle environments for over 25 years and is purpose-built for the challenge of replicating Oracle data to heterogeneous targets including Microsoft SQL Server and PostgreSQL, with a design philosophy centred on zero impact to the source database.
The key architectural decision in SharePlex is its use of log-based Change Data Capture. Rather than querying Oracle production tables or using database triggers to detect changes, SharePlex reads Oracle's redo logs — the same transaction journal Oracle uses internally for crash recovery. This means:
Changes captured from the redo logs are transmitted to the target system and applied to PostgreSQL with full transactional consistency. The replication is asynchronous, which means the Oracle transaction commits without waiting for PostgreSQL to acknowledge receipt — ensuring Oracle performance is entirely unaffected — while SharePlex guarantees delivery and typically maintains a lag of milliseconds to a few seconds.
SharePlex supports full Oracle-to-PostgreSQL replication, including the ability to replicate from multiple Oracle sources to a single PostgreSQL target, from a single Oracle source to multiple PostgreSQL targets, and to filter replication at the column or row level. A single capture process can simultaneously feed a PostgreSQL replica and a Kafka stream, a data warehouse, or any other target — with each receiving only the data it needs.1
SharePlex is a powerful and proven replication engine, but deploying it at enterprise scale — across complex Oracle schemas with thousands of tables, varied data volumes, and a mix of insert-heavy and update-heavy patterns — requires careful design. An incorrectly configured replication queue can overwhelm source system resources, create bottlenecks at the target, or produce replication errors that require manual intervention.
This is the problem Osprey solves.
Osprey is a proprietary tool developed by Pebble IT that acts as an intelligent analysis and orchestration layer between the Oracle source and SharePlex. In every Pebble IT-managed Oracle-to-PostgreSQL engagement, Osprey is used to:
Oracle databases in production environments are rarely homogeneous. A typical enterprise Oracle schema might include:
Without intelligent queue design, SharePlex may attempt to replicate all of these through the same queue, creating resource contention and uneven latency. Osprey classifies each table type and designs separate, purpose-optimised queues that match the replication load to the available resources on both source and target systems.
Osprey's intelligence is what makes the SharePlex replication both operationally safe and cost-efficient. By minimising the time SharePlex needs to be active — and by preventing resource exhaustion on production servers — Osprey also helps minimise the SharePlex licensing cost itself, which is calculated based on usage across both the Oracle and PostgreSQL environments.
The financial case for Oracle offloading to PostgreSQL is compelling, but it is often incorrectly stated as a cost reduction exercise when in fact the primary value is cost avoidance — preventing expenditure that would otherwise be necessary as the business grows.
Cost avoidance is the prevention of a future expense. It does not appear as a saving on a cost centre comparison because there is no prior-period spend to compare against — but it is real money that the organisation retains. In technology budgeting, cost avoidance is frequently undervalued relative to cost reduction, yet it is often the larger of the two over a multi-year horizon.
In the context of Oracle and PostgreSQL, cost avoidance occurs when:
The following table illustrates the five-year cost of ownership for a typical mid-sized enterprise Oracle deployment compared to an equivalent PostgreSQL environment. Figures are indicative and based on published pricing and industry benchmarks.
Source: Pebble IT analysis based on Oracle published pricing and PostgresPURE subscription costs.
This comparison represents only the licensing and support component of Oracle cost. It does not include the cost of Oracle options and packs (Partitioning, Diagnostics & Tuning, Real Application Clusters), Oracle audit risk mitigation, or the opportunity cost of constrained compute capacity. When these are included, the total cost differential is substantially larger.
Whilst the above table compares ownership of the complete use of Oracle verses PostgreSQL, imagine that the Oracle database licensing had to increase or that the initial Oracle license purchase could be reduced because of PostgreSQL ? This is where the cost-avoidance lives.
One of the most significant structural advantages of PostgreSQL in an offloading context is that it imposes no licensing constraint on server scale. An organisation can deploy PostgreSQL on a server with 128 CPU cores and 2 TB of RAM and pay nothing for the database license. This means that as the reporting and analytics workload grows — more users, more complex queries, more data — the response is simply to add hardware. There is no licensing multiplier, no processor count negotiation, no Oracle audit risk.
By contrast, adding equivalent compute capacity to an Oracle environment at these scales represents a multi-million dollar licensing commitment, with annual support costs to match.
The exception to this is if the organisation chose to subscribe to Splendid Data’s PostgresPURE product that represents a collection of pre-tested libraries and extensions with the PostgreSQL version and the ability to update twice annually as a bundle in a similar vein to patching an Oracle database. Both vCPU and Server based pricing is available and is typically 90%+ less than the equivalent Oracle support cost.
Similarly, there are PostgreSQL services in Azure, Google and AWS that will additional cost as the instance size increased, whilst the PostgreSQL software has no license cost, the infrastructure cost increases so careful consideration of resource sizing is required to avoid waste and arrive at efficient spend.
The offloading and migration of Oracle workloads to PostgreSQL is not a niche strategy — it is one of the defining database trends of the mid-2020s, with significant and accelerating adoption across enterprise and government sectors worldwide.
As of 2025, PostgreSQL holds a 16.85% share of the relational database market — making it the second most widely used open-source database globally — and it is the fastest-growing database platform for three consecutive years. It is the production database of choice for organisations including Apple, Spotify, Instagram, Reddit, and NASA, processing billions of transactions daily. Enterprises report Total Cost of Ownership reductions of 70–90% after migrating from Oracle to PostgreSQL.
In the financial services, retail, and healthcare sectors in particular, the shift is accelerating. A North American retail chain migrating a 7 TB Oracle database to PostgreSQL realised A$420,000 in avoided licensing and support costs, A$135,000 in operational savings, and achieved payback within nine months. Reporting workload performance improved by ~70% — a direct benefit of PostgreSQL's ability to run on unconstrained, optimised hardware.3
Government departments at national, state, and local levels across Europe, North America, Asia-Pacific, and Australia are actively evaluating and executing Oracle-to-PostgreSQL strategies. The drivers are consistent:
In New South Wales, Pebble IT has worked directly with state government agencies to deploy Oracle Standard Edition with open-source alternatives for replication, encryption, and high availability — achieving enterprise-grade resilience at a fraction of Oracle Enterprise Edition cost. The same principles apply to the offloading strategy described in this article.
A particularly common and underappreciated scenario is the Oracle database that is under-performing not because of its transactional workload, but because of the reporting and integration load surrounding it. DBAs in this situation often observe:
This is precisely the scenario where offloading to PostgreSQL delivers the most immediate operational benefit. By redirecting reporting traffic to PostgreSQL, the Oracle database's compute resources are freed for the transactional workload they were licensed to support. Many organisations in this situation have been able to defer or eliminate Oracle hardware and license upgrades that were being driven entirely by reporting demand — not by their core operational needs.
Beyond operational reporting, the PostgreSQL replica created by SharePlex replication becomes a foundation for additional strategic workloads that would be prohibitively expensive to run against Oracle.
Data warehouse architectures typically involve scheduled or near-real-time extraction of operational data from source systems. When the source is Oracle, this extraction adds to the licensed processor load — every ETL job reading Oracle tables consumes CPU cycles that may impact the end user experience.
When the PostgreSQL replica is used as the data warehouse source instead:
The emergence of AI and machine learning as standard enterprise capabilities creates a new category of database compute demand. Training datasets, feature extraction, model inference pipelines, and embedding generation all require access to operational data at scale. Running these workloads against Oracle is not just expensive — it is architecturally inappropriate. AI workloads are read-intensive, often involve full table scans or complex aggregations, and may run for extended periods.
PostgreSQL is an ideal platform for AI and ML data sourcing:
AI models drawing on data from a PostgreSQL replica of Oracle data have zero impact on Oracle's licensed processor utilisation. This is perhaps the most future-proof aspect of the offloading strategy: as AI and data workloads grow — and they will — the cost will be hardware and compute, not Oracle licenses.
An Oracle offloading project using SharePlex and Osprey is a structured, phased engagement. Pebble IT's approach involves:
A key security and governance aspect of the offloading architecture is the enforcement of read-only access on the PostgreSQL replica. This is implemented at the PostgreSQL account and schema level, ensuring that:
This approach also simplifies compliance: the PostgreSQL replica can be audited and reported on without concern for write activity, and access can be granted broadly to business users without the security risk of inadvertent data modification. Whilst local access audit data can be captured, it is a very complex scenario to have bi-directional replication unless the data can only be subject to DML at one database only.
A particular strength of this strategy is its platform independence. Oracle's licensing model varies in complexity between on-premise and cloud deployments — cloud environments introduce additional calculation rules and restrictions — but the offloading principle applies equally in both contexts:
Oracle Optimisation through PostgreSQL offloading is not a theoretical strategy. It is a proven, practical approach that organisations and government departments are implementing today — in Australia and around the world — to manage Oracle licensing costs, prevent future expenditure, and free Oracle's licensed compute capacity for the transactional workloads it was designed and licensed to serve.
The combination of Quest SharePlex's proven, non-intrusive replication technology and Pebble IT's Osprey tool for intelligent queue design creates an enterprise-grade offloading capability that is operationally safe, technically sound, and financially compelling. PostgreSQL — particularly in a managed, enterprise-ready distribution such as PostgresPURE from Splendid Data — provides the target platform with the reliability, scalability, and feature depth that enterprise and government workloads require.
For technology leaders reviewing their Oracle footprint in the context of rising costs, expanding data volumes, growing user populations, and the emergence of AI and analytics workloads, this strategy offers a clear path forward:
The organisations that act on this now will be the ones that control their Oracle costs through the next decade. Those that wait will find themselves purchasing licenses to support workloads that could have been running on PostgreSQL at no cost.
For further information on Pebble IT's Oracle Optimisation services, Osprey, and the PostgresPURE platform, visit pebbleit.com.au. For Quest SharePlex information, visit quest.com/products/shareplex.
1 Quest SharePlex — log-based asynchronous CDC replication for Oracle and PostgreSQL. quest.com/products/shareplex
2 Pebble IT — Why PostgreSQL Should Be Part of Your Oracle Optimisation Strategy (February 2026). pebbleit.com.au/insight/why-postgresql-should-be-part-of-your-oracle-optimisation-strategy
3 OptiSol Business Solutions — Why Enterprises Across BFSI, Retail and Healthcare Are Moving from Oracle to PostgreSQL in 2025. optisolbusiness.com/insight/why-enterprises-across-bfsi-retail-and-healthcare-are-moving-from-oracle-to-postgresql-in-2025

