Paritas In development
An Oracle-compatible PostgreSQL, built around one honest promise: we can tell you exactly where compatibility ends — for your code, with measured evidence — and close the gaps that matter to you.
Paritas is early and not for sale yet. This page describes the problem and our approach. The differential test harness behind it already runs — we are happy to show it live.
The dangerous half of a migration is invisible
When a company moves off Oracle, everyone focuses on converting the code — the visible half. The invisible half is that PostgreSQL is not Oracle: in places it computes a different answer to the same expression. Not an error. A different number.
One expression, two different answers
A real result, measured this week on live engines. A floating-point expression near the top of the range:
| Engine | Result | |
|---|---|---|
| Oracle | inf | the source of truth |
| PostgreSQL | error — value out of range | rejects it outright |
| Paritas | inf | matches Oracle ✓ |
Oracle returns infinity; stock PostgreSQL raises an out-of-range error instead. If a calculation relied on that behaviour, it would convert cleanly and then fail in production on a real value. Paritas returns infinity, like Oracle — because we measured the difference rather than guessing at it.
We built the test harness before the database
The moat is not the database — anyone can fork one. It's a differential test harness: Oracle and PostgreSQL running side by side with Paritas on one machine. The same SQL goes to all of them, and every answer is compared against Oracle. A difference is only real once it is measured on a live engine — never assumed from a manual.
Oracle — source of truth
Every expression's correct answer is defined by what a real Oracle instance actually returns, not by what the documentation says it should.
PostgreSQL — the baseline
Stock PostgreSQL shows where a straight migration silently diverges — the gaps a code converter can't see because they aren't syntax.
Paritas — the destination
Built on Apache-2.0-licensed open-source PostgreSQL technology, with proper attribution, and hardened one measured difference at a time.
Knowing the limits is the product
Any architect will test a compatibility claim within an hour. Say "Oracle compatible" without limits and you lose the account the moment they find the first gap. So we publish where it ends. For example, Oracle has no integer type, so SELECT 10/4 returns 2.5; PostgreSQL-family engines return 2 — an open gap we flag rather than hide.
It plugs straight into pgrecon
pgrecon tells you what your Oracle estate contains and what a migration will cost. The Paritas harness tells you which of that estate behaves differently on the destination — measured, per expression. Same pipeline: know the scope, then know the risk, before you commit.
What exists today
We would rather you hear the limits now than in six months.
Built and working
- The differential harness, engines verified side by side
- Paritas builds, installs and runs, fully rebranded
- A real compatibility fix where we match Oracle
- Full regression suite passing at parity with upstream
Upstream, done right
Paritas builds on Apache-2.0-licensed open-source technology, so it is fully legal, with proper attribution files. Where we find a defect that belongs upstream, we send it back with a reproduction the maintainers can run — building credibility in the PostgreSQL world rather than maintaining a private fork of everything.
Not built yet
Almost everything else. Paritas cannot be bought today, and we would not list it as a shippable product. We are telling you now because it is where this work goes — and it explains why our assessment tooling is built the way it is.
Moving off Oracle? Let's measure the risk
We can show you the harness running — it's more convincing to watch than to describe — and tell you exactly where compatibility ends for your code.