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Databases · head to head

FaunaDB vs TiDB

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
TiDB logo

TiDB

Databases

Apache 2.0 distributed SQL database with MySQL wire compatibility and a separate columnar replica for analytical queries.

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.; TiDB a production cluster needs several placement driver, storage and SQL nodes before it is fault tolerant, so the minimum viable footprint is far larger than a MySQL server and TiDB is never the economical choice for a small database.
  • They diverge on capability: FaunaDB covers Document-relational model, TiDB covers MySQL wire compatibility.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which FaunaDB and TiDB actually diverge.

Attributes where FaunaDB and TiDB differ
AttributeFaunaDBTiDB
PlatformsWebCloud, AWS, Azure, Google Cloud Platform, Self-managed
Founded20122015

Identical on both: starting price (Free), pricing model (freemium), 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
  • HTTPS access
  • User-defined functions
  • Attribute-based access control
  • Document history
  • Event streaming
  • Apache 2.0 core

Only in TiDB

  • MySQL wire compatibility
  • Horizontal write scaling
  • TiFlash columnar replica
  • Automatic rebalancing
  • Raft replication
  • Apache 2.0 licence
  • Online schema change
  • Change data capture

Both cover

  • Distributed ACID transactions

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 TiDB
  • Extracting historical data from a Fauna dataset that can no longer be reached through the hosted APInot TiDB
  • Studying a production implementation of deterministic distributed transactions, since the full server source is now readable under Apache 2.0not TiDB
  • Forking the engine deliberately, where an organisation has JVM and distributed-systems staff and wants a document-relational store it fully controlsnot TiDB

TiDB

  • A MySQL workload that has hit the write ceiling of a single primary and would otherwise need an application-level sharding layernot FaunaDB
  • Reporting that must run against current transactional data, where the columnar replica removes the delay and the cost of an ETL pipelinenot FaunaDB
  • Multi-region deployments needing a single logical database with automatic failover rather than manual primary promotionnot FaunaDB
  • Migrating off a sharded MySQL estate where the sharding logic in the application has become the main source of bugs and operational toilnot 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.

TiDB

  • A production cluster needs several placement driver, storage and SQL nodes before it is fault tolerant, so the minimum viable footprint is far larger than a MySQL server and TiDB is never the economical choice for a small database.
  • Every transaction takes a timestamp from the placement driver and crosses the network to storage nodes, so simple point queries are slower than on single-node MySQL and latency-sensitive paths need to be measured, not assumed.
  • MySQL compatibility is at the wire and dialect level but not complete; stored procedures, triggers and events are not supported, so an application that pushed logic into the database cannot simply be repointed.
  • The columnar replica is an extra full copy of the data on its own nodes, so hybrid analytics roughly doubles storage and adds hardware that must be sized and paid for separately.
  • Operating it well requires cluster-specific expertise in TiUP or the Kubernetes operator, region hot spots, and rebalancing behaviour, so the licence is free but the running cost includes an engineer who understands distributed storage.

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

TiDB

Free
  • ServerlessFree
    • 5GB storage
    • 50M request units
    • Free forever tier
  • Dedicated$250/month
    • Dedicated resources
    • SLA guarantees
    • Enterprise support

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 TiDB if

  • You need mysql wire compatibility.
  • You want to start without paying.
  • You work on Cloud, AWS, Azure, Google Cloud Platform, Self-managed.
  • You also want horizontal write scaling.
TiDB review

Questions people ask

Is FaunaDB or TiDB better?
Neither clearly leads. FaunaDB starts at Free and TiDB at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, FaunaDB or TiDB?
FaunaDB starts at Free and TiDB at Free.
Does FaunaDB or TiDB run on more platforms?
FaunaDB runs on Web. TiDB runs on Cloud, AWS, Azure, Google Cloud Platform, Self-managed.
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 TiDB is typically brought in for.
What can FaunaDB do that TiDB cannot?
FaunaDB covers Document-relational model, FQL v10, HTTPS access, User-defined functions. TiDB covers MySQL wire compatibility, Horizontal write scaling, TiFlash columnar replica, Automatic rebalancing. Both handle Distributed ACID transactions.

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.

TiDB: Is TiDB a drop-in replacement for MySQL?

At the protocol and dialect level it is close, and most applications connect unchanged. Stored procedures, triggers and events are not supported, and latency characteristics differ, so it needs testing rather than assumption.

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.

TiDB: What licence is it under?

Apache 2.0, for both TiDB and the underlying TiKV storage engine. TiKV is a graduated CNCF project, which is a meaningful governance signal in a market where several competitors moved to source-available licences.

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.

TiDB: Do I need TiFlash?

Only for analytical queries. It is an optional columnar replica; without it TiDB is a distributed transactional database. With it you get analytics on live data at the cost of an additional full copy.

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.

TiDB: Is the managed cloud the same software?

TiDB Cloud runs the same engine, with the control plane, scaling and operational tooling provided as a service. The entry tier is metered differently from a dedicated cluster, so the cost model rather than the engine is what changes.

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.

TiDB: When is TiDB the wrong choice?

When the database is small enough for one server, when latency on single-row lookups is the primary constraint, or when the application depends on MySQL stored procedures and triggers.

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