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Databases · head to head

FaunaDB vs IBM Db2

FaunaDB logo

FaunaDB

Databases

Document-relational database whose hosted service closed in 2025 and whose core is now unmaintained Apache 2.0 code.

From
Free
Rated
-
Full reviewWebsite
IBM Db2 logo

IBM Db2

Databases

The AI-powered database built for demanding enterprise workloads

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: FaunaDB the hosted service was wound down in 2025, so there is no managed Fauna to buy; every remaining user either operates a JVM cluster themselves or migrates, and both are projects rather than tasks.; IBM Db2 cloud-based Db2 is newer than mainframe version; some legacy mainframe features not yet available in cloud
  • They diverge on capability: FaunaDB covers Document-relational model, IBM Db2 covers AI-powered Query Optimization.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which FaunaDB and IBM Db2 actually diverge.

Attributes where FaunaDB and IBM Db2 differ
AttributeFaunaDBIBM Db2
Pricing modelfreemiumUnknown
PlatformsWebIBM Cloud, On-premises (mainframe), Linux, UNIX
Founded20121983

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Databases).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in FaunaDB

  • Document-relational model
  • FQL v10
  • Distributed ACID transactions
  • HTTPS access
  • User-defined functions
  • Attribute-based access control
  • Document history
  • Event streaming

Only in IBM Db2

  • AI-powered Query Optimization
  • Data Virtualization
  • Advanced Compression
  • pureScale Clustering
  • BLU Acceleration
  • Workload Management
  • Federated Queries
  • IBM Cloud

What people use each for

The jobs each tool is most often brought in to do.

FaunaDB

  • Keeping an existing Fauna-backed application alive on self-hosted infrastructure while a migration is planned and fundednot IBM Db2
  • Extracting historical data from a Fauna dataset that can no longer be reached through the hosted APInot IBM Db2
  • Studying a production implementation of deterministic distributed transactions, since the full server source is now readable under Apache 2.0not IBM Db2
  • Forking the engine deliberately, where an organisation has JVM and distributed-systems staff and wants a document-relational store it fully controlsnot IBM Db2

IBM Db2

  • Transaction processingnot FaunaDB
  • Data storagenot FaunaDB
  • Application backendnot FaunaDB
  • Reportingnot FaunaDB
  • Data analyticsnot FaunaDB

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

FaunaDB

  • The hosted service was wound down in 2025, so there is no managed Fauna to buy; every remaining user either operates a JVM cluster themselves or migrates, and both are projects rather than tasks.
  • The open-sourced repository has had no substantive activity since May 2025 and the drivers were frozen alongside it, so you inherit responsibility for security patches in a Scala distributed database that almost nobody else is running.
  • FQL has no wire or dialect compatibility with anything else, so migrating off is a rewrite of every query, index and access rule in the application rather than a data export.
  • No BI tool, ORM or CDC connector speaks FQL, so reporting and analytics always required exporting the data first, and that export tooling is now also unmaintained.
  • The community was small before the shutdown and has dispersed since, so operational answers, tuning advice and people who have run a Fauna cluster in anger are all scarce when something breaks.

IBM Db2

  • Cloud-based Db2 is newer than mainframe version; some legacy mainframe features not yet available in cloud
  • Pricing complexity with hourly billing for compute and storage can result in unpredictable costs
  • Less community support and documentation compared to open-source alternatives like PostgreSQL
  • Requires IBM expertise and tools for optimal configuration and tuning
  • Migration from mainframe Db2 to cloud Db2 requires careful planning and testing

Pricing, plan by plan

FaunaDB

Free
  • FreeFree
    • 100K read ops
    • 50K write ops
    • 1GB storage
  • Pro$25/month
    • Pay per use
    • Priority support
    • Advanced features

IBM Db2

Free
  • Free TierFree
    • Entry-level exploration
    • Limited resources
  • Standard$99/month
    • Production-ready workloads
    • Shared computing resources
  • Enterprise$969/month
    • Dedicated computing resources
    • Enhanced capabilities

Which should you pick?

Choose FaunaDB if

  • You need document-relational model.
  • You want to start without paying.
  • You also want fql v10.
FaunaDB review

Choose IBM Db2 if

  • You need ai-powered query optimization.
  • You want to start without paying.
  • You work on IBM Cloud, On-premises (mainframe), Linux, UNIX.
  • You also want data virtualization.
IBM Db2 review

Questions people ask

Is FaunaDB or IBM Db2 better?
Neither clearly leads. FaunaDB starts at Free and IBM Db2 at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, FaunaDB or IBM Db2?
FaunaDB starts at Free and IBM Db2 at Free.
Does FaunaDB or IBM Db2 run on more platforms?
FaunaDB runs on Web. IBM Db2 runs on IBM Cloud, On-premises (mainframe), Linux, UNIX.
Can I use FaunaDB for free?
Both have a free tier, so you can try either at no cost before committing.
What is FaunaDB best used for?
FaunaDB is most often used for keeping an existing fauna-backed application alive on self-hosted infrastructure while a migration is planned and funded, extracting historical data from a fauna dataset that can no longer be reached through the hosted api, studying a production implementation of deterministic distributed transactions, since the full server source is now readable under apache 2.0, forking the engine deliberately, where an organisation has jvm and distributed-systems staff and wants a document-relational store it fully controls. Of those, keeping an existing fauna-backed application alive on self-hosted infrastructure while a migration is planned and funded and extracting historical data from a fauna dataset that can no longer be reached through the hosted api are not what IBM Db2 is typically brought in for.
What can FaunaDB do that IBM Db2 cannot?
FaunaDB covers Document-relational model, FQL v10, Distributed ACID transactions, HTTPS access. IBM Db2 covers AI-powered Query Optimization, Data Virtualization, Advanced Compression, pureScale Clustering.

Answered from the vendors’ own pages

FaunaDB: Can I still sign up for Fauna as a service?

No. Fauna Inc. wound down the hosted service in 2025 and the company website is no longer serving. The only way to run Fauna now is to build and operate the open-sourced server yourself.

IBM Db2: What is IBM Db2?

IBM Db2 is a cloud-based relational database management system designed for enterprise data management. It evolved from IBM's research into relational databases in the 1970s and launched for mainframe systems in 1983.

Source
FaunaDB: What licence is the open-sourced code under?

Apache 2.0, with the copyright held by a FaunaDB Foundation. That is a permissive OSI licence with no competing-use clause, so you may run it, modify it and even offer it as a service.

IBM Db2: What are the pricing tiers for IBM Db2 cloud database?

IBM Db2 offers a perpetually free tier for exploration, Standard tier starting at $99/month (billed hourly), and Enterprise tier starting at $969/month (billed hourly). Storage costs $0.000282 per GB per hour across tiers.

Source
FaunaDB: Is the open source version the same software that ran the cloud?

It is the core database engine. The control plane, billing, dashboard and multi-tenant operational tooling that made it a service are not part of the release, so you are running the engine, not the product.

IBM Db2: Does Db2 support automatic failover and disaster recovery?

Yes. Db2 includes HADR (High Availability Disaster Recovery) with multizone region support, point-in-time recovery, built-in self-service snapshots, and geo-replicated data recovery backups.

Source
FaunaDB: What should I migrate to?

There is no drop-in target. Teams that valued the document model with relationships usually land on Postgres with JSONB, and teams that valued the serverless HTTP access pattern usually land on DynamoDB or a managed Postgres with an HTTP driver. Either way the query layer is rewritten.

IBM Db2: Can Db2 scale horizontally?

Yes. Db2 supports both vertical and horizontal scaling through its pureScale architecture, allowing it to handle growing data volumes while maintaining performance for mission-critical applications.

Source
FaunaDB: How hard is it to self-host?

It builds as a fat JAR and runs as a multi-node JVM cluster. There is an OPERATING.md, but no supported packaging, no operator, no upstream releases and no support contract, so budget for a distributed-systems engineer, not a container.

IBM Db2: How long has DB2 been in production?

DB2 launched in June 1983 on the MVS operating system and has operated for over 40 years. It remains the foundational database for the largest enterprises globally, managing data for financial, retail, healthcare, and insurance institutions.

Source
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