Coverage · Amazon RDS
Reserved DB instances, matched to what's actually running.
RDS reservations flex more than most people expect within a class type, and not at all across engines. The engine you buy is the engine you're stuck with for the whole term — no convertible option, no resale. Reserver matches every reservation to the database actually running so a mismatch shows up immediately, not on next quarter's bill.
- Must match exactly
- Instance family (class type), database engine, region
- Can flex
- Size within the class type by normalized units, and freely between Single-AZ and Multi-AZ — on Db2, MariaDB, MySQL, Oracle BYOL and PostgreSQL only. No size flexibility on SQL Server or Oracle License Included, and no convertible option on any engine.
- Term
- 1-year or 3-year
- Payment option
- No Upfront, Partial Upfront, or All Upfront
- Exchange & resale
- None — no modification, no exchange, no Marketplace resale
Discount ceilings per AWS published pricing; your actual rates depend on instance class, term, and payment option — Reserver shows you the exact math for your fleet.
Where the money goes missing
Three ways Amazon RDS leaks.
The leak
The engine is the one thing that never flexes
A PostgreSQL reservation never discounts a MySQL or Aurora instance, whatever its size. Engine is fixed at purchase, so a mid-term migration strands the old reservation entirely while the new database bills on-demand — and on SQL Server or Oracle License Included there's no size flexibility either, making those genuinely one-shot on class as well.
What Reserver does
Every dimension shown on every match. Reserver's coverage map shows each RDS reservation against the database actually running — engine, class type, deployment option and region side by side — so an engine mismatch shows up as unmatched capacity immediately, not months later.
The leak
The renewal cliff, RDS edition
RDS Reserved Instances don't auto-renew any more than EC2's do. A one- or three-year term ends quietly and the database — often the single most expensive instance in the fleet — reverts to on-demand.
What Reserver does
Expiry radar on every RDS reservation. Reserver tracks every RDS reservation's end date and flags it before the term lapses, so the renewal decision gets made on purpose.
The leak
No exchange, no resale, no safety valve
Unlike EC2, RDS has no Convertible option and no Marketplace resale. Size flexibility absorbs a class-size mistake within the same class type, but a reservation bought against the wrong engine — or the wrong class type entirely — is stuck for the rest of the term with no way out.
What Reserver does
Get the engine and class type right before you buy. Reserver's recommendations show the exact engine, class type, and region the reservation needs — so the decision that can't be undone later is made with the fleet in front of you, not from a guess.
What Reserver does
Every Amazon RDS reservation, accounted for.
Full RDS inventory scan
Every instance's class, engine, deployment option, and region — scanned directly from the account, not estimated.
RDS reservation ledger
Every RDS reservation you own: term, payment option, expiry date, and what it's actually covering right now.
One-click RDS purchasing
Accept a recommendation and Reserver buys the reservation through the AWS purchase APIs — no console safari.
Expiry radar & renewal autopilot
Every RDS reservation's end date is tracked and flagged ahead of the lapse — or re-bought automatically on Autopilot.
At your size
Same Amazon RDS, different scale.
A handful of RDS instances on one engine is easy to lose track of on a small team — the renewal date is the whole risk.
A renewal missed by 14 days ≈ $92 — pays for about 3 weeks of Reserver.
Dozens of RDS instances across several engines means an engine mismatch or a stranded class type compounds between reviews.
A renewal missed by 14 days ≈ $951 — pays for about 6 months of Reserver.
Hundreds of RDS instances across many accounts and engines — a single unmatched reservation is easy to miss without one coverage view.
A renewal missed by 14 days ≈ $6,904 — pays for a year or more of Reserver.
The same flat price whether you track 10 reservations or 10,000 — never a percentage of what you save.
Keep reading
Go deeper on Amazon RDS.
Glossary
Guides
FAQ
Amazon RDS questions
Does an RDS reservation follow a database if we change its engine?
No. The engine is fixed for the whole term — there's no Convertible option like EC2 has, so changing engine mid-term leaves the old reservation covering nothing. Size is a different story: on Db2, MariaDB, MySQL, Oracle BYOL and PostgreSQL the benefit applies across sizes within the same class type, and across Single-AZ and Multi-AZ, by normalized units.
Can we resell an RDS reservation we don't need anymore?
No — the RI Marketplace only exists for EC2 Standard RIs. An RDS reservation bought against the wrong class or engine has no resale option; it runs out its term regardless.
What happens to our reservation if we move a database to Multi-AZ?
On the size-flexible engines, AWS keeps applying the benefit — it moves freely between Single-AZ and Multi-AZ within the same class type, measured in normalized units, so a Single-AZ reservation can cover a smaller Multi-AZ deployment. Reserver shows deployment option on every instance and every reservation, so you can see exactly where the discount is landing rather than inferring it from the bill.
What happens when an RDS reservation term ends?
Nothing changes about the running database — it doesn't restart or degrade. The discount just stops, and usage reverts to the on-demand rate the instant the term lapses. Reserver's expiry radar flags this before it happens.
Stop overpaying for a steady fleet.
Reserver is in early access. Join the list and we'll onboard you as capacity opens up — first recommendation within minutes of connecting.