How are Adabas and Db2 for z/OS licensed?

Both price on mainframe capacity in MSU, but inside different vendor models. Adabas, from Software AG's standalone Adabas and Natural business, is typically licensed on MSU capacity tied to the machines and LPARs where it runs, enforced through machine specific keys, often under long lived contracts. Db2 for z/OS is an IBM product, licensed under IBM's Monthly License Charge framework with sub-capacity reporting through SCRT, and increasingly under Tailored Fit Pricing consumption models. So both are capacity based, but the Adabas conversation is about a legacy contract with one focused vendor, while the Db2 conversation sits inside the wider IBM z/OS software relationship.

Is migrating from Adabas to Db2 for z/OS worth it?

For most large estates, not as a near term cost play. Applications built against the Adabas data model and the Natural language are tightly coupled to it, so a migration to Db2 is a multi year, high risk program involving data model redesign, application rewrite or conversion, extensive testing, and parallel running. The licensing saving rarely clears that cost on its own. Migration makes sense when it rides a broader modernization mandate, a platform exit, or a strategic decision already funded for other reasons. Absent that, the more reliable value of the Db2 option is as leverage on the Adabas renewal, not as an executed project.

How do you use the migration option as leverage?

Prepare it seriously rather than threaten it casually. A credible, costed migration plan, with a realistic timeline, scope, and risk assessment, changes the Adabas renewal conversation because the vendor knows the alternative is genuine even though execution is unlikely. The leverage comes from preparation, not bluff: a plan you could defend in front of your own board is one the vendor takes seriously. Paired with reconciling licensed against consumed Adabas capacity and timing the renewal on the 18 month runway, the option disciplines the number while you stay on the platform.

Adabas vs Db2 for z/OS: Cost

Adabas vs Db2 for z/OS: the migration you price but rarely run.

Software AG Adabas and IBM Db2 for z/OS both price on MSU capacity, but the real question buyers ask is whether to migrate off Adabas to Db2. For most large estates the migration is a multi year, high risk program. The credible plan is worth more as leverage on the Adabas renewal than as an executed project.

Prepare the migration seriously and run it only when a broader mandate funds it. Moving from Adabas to Db2 for z/OS means redesigning the data model, converting or rewriting applications built on Adabas and Natural, and a long, costly, risky program of testing and parallel running. The licensing saving alone almost never clears that cost. What does pay is using a credible, costed migration plan as leverage on the Adabas renewal: the vendor takes a genuine alternative seriously even when execution is unlikely. Reconcile your Adabas capacity, build the Db2 option as something you could defend to your board, and most often the right outcome is a better Adabas deal, not a migration.

Adabas vs Db2 for z/OS, the licensing and migration levers compared
Dimension	Adabas	Db2 for z/OS
Vendor	Software AG, standalone Adabas and Natural business	IBM
Data model	Inverted list, non relational, tightly coupled to Natural	Relational, SQL, broad tooling and skills base
Licensing metric	MSU capacity, machine specific keys	MSU capacity, MLC with SCRT sub-capacity, TFP options
Contract context	Often long lived, focused single vendor agreement	Inside the wider IBM z/OS software relationship
Skills availability	Narrowing, specialized Adabas and Natural talent	Wide, SQL and Db2 skills broadly available
Switching cost	n/a, incumbent	High, multi year migration and application rework

Adabas vs Db2 for z/OS, the licensing and migration levers compared

Dimension

Adabas

Db2 for z/OS

Vendor

Software AG, standalone Adabas and Natural business

IBM

Data model

Inverted list, non relational, tightly coupled to Natural

Relational, SQL, broad tooling and skills base

Licensing metric

MSU capacity, machine specific keys

MSU capacity, MLC with SCRT sub-capacity, TFP options

Contract context

Often long lived, focused single vendor agreement

Inside the wider IBM z/OS software relationship

Skills availability

Narrowing, specialized Adabas and Natural talent

Wide, SQL and Db2 skills broadly available

Switching cost

n/a, incumbent

High, multi year migration and application rework

This is rarely a clean either or; it is a stay and negotiate decision against a real but expensive exit. Use it this way:

Stay on Adabas and negotiate if

The applications are stable, deeply coupled to Adabas and Natural, and not part of a funded transformation
A credible, costed Db2 migration plan gives you a defensible walk away to discipline the renewal
Reconciling licensed against consumed Adabas capacity and timing the renewal capture most of the available saving

Genuinely consider migrating to Db2 if

A broader modernization or platform strategy already funds the application rework the migration requires
The Adabas and Natural skills risk is becoming acute and Db2's wider talent pool materially de risks the estate
The long run total cost, licensing plus skills plus agility, favors relational once the migration is amortized

The foundational discipline either way is to cost the migration honestly. An inflated estimate weakens your leverage; a credible one strengthens it and tells you the truth about whether to move.

How are they licensed?Both on MSU capacity. Adabas under a focused, often legacy Software AG contract with machine keys; Db2 under IBM MLC with SCRT sub-capacity and TFP options.

Is migrating worth it?Rarely as a near term cost play. The application rework is a multi year program. It pays when a broader modernization mandate already funds it.

How do you use the option as leverage?Prepare a credible, costed migration plan you could defend to your board. The vendor takes a genuine alternative seriously even when execution is unlikely.

What is the first move?Cost the migration honestly and reconcile your Adabas licensed capacity. Both sharpen the renewal whether or not you ever migrate.

The exit you cost well is the renewal you win.

Explainers: the mainframe exit question and SCRT sub-capacity reporting explained. Related comparison: IDMS vs Db2. Products: Adabas licensing and Natural licensing. Hubs and commercial: the Software AG buyer side guide, the IBM buyer side guide, and Software AG renewal advisory.

Adabas vs Db2 for z/OS: the migration you price but rarely run.

The verdict

Head to head

Who should pick which

Frequently asked

You may never migrate. Cost it as if you might.