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Databases · head to head

PostgreSQL vs RabbitMQ

PostgreSQL logo

PostgreSQL

Databases

The world's most advanced open source relational database

From
Free
Rated
-
Full reviewWebsite
RabbitMQ logo

RabbitMQ

Databases

Open-source message broker supporting AMQP and other protocols

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: PostgreSQL requires manual scaling across multiple machines for very large deployments; RabbitMQ not built for replay: once consumed, a message is gone, which is exactly what Kafka exists to change
  • They diverge on capability: PostgreSQL covers ACID Compliance, RabbitMQ covers Flexible routing.

Where they differ

Only the attributes on which PostgreSQL and RabbitMQ actually diverge.

Attributes where PostgreSQL and RabbitMQ differ
AttributePostgreSQLRabbitMQ
Pricing modelUnknownOpen source, no licence fee; managed services billed separately
PlatformsLinux, Windows, macOS, BSD, UnixLinux, macOS, Windows, Docker, Kubernetes
Founded1996Unknown

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 PostgreSQL

  • ACID Compliance
  • JSON/JSONB Support
  • Full-text Search
  • Extensibility
  • Advanced Indexing
  • Partitioning
  • Replication
  • pgAdmin

Only in RabbitMQ

  • Flexible routing
  • Multiple protocols
  • Management UI
  • Clustering and mirroring

What people use each for

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

PostgreSQL

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

RabbitMQ

  • Distributing background jobs to a pool of workers with retriesnot PostgreSQL
  • Decoupling services that need delivery rather than a replayable historynot PostgreSQL
  • Routing messages by pattern to different consumers from one publishernot PostgreSQL

Where each one falls short

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

PostgreSQL

  • Requires manual scaling across multiple machines for very large deployments
  • Performance tuning requires deep knowledge of database internals
  • No built-in graphical admin interface; command-line tools are primary method

RabbitMQ

  • Not built for replay: once consumed, a message is gone, which is exactly what Kafka exists to change
  • Throughput ceilings are lower than a log-based platform under very heavy streaming loads
  • Queues that build up degrade broker performance, so consumer lag is an operational problem rather than just a backlog
  • Clustering and partition behaviour has historically been a source of hard-to-diagnose problems

Pricing, plan by plan

PostgreSQL

Free

No published plan breakdown. See the PostgreSQL review.

RabbitMQ

Free
  • RabbitMQFree
    • Full functionality
    • Self-hosted
    • No usage limits

Which should you pick?

Choose PostgreSQL if

  • You need acid compliance.
  • You want to start without paying.
  • You work on Linux, Windows, macOS, BSD, Unix.
  • You also want json/jsonb support.
PostgreSQL review

Choose RabbitMQ if

  • You need flexible routing.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, Docker, Kubernetes.
  • You also want multiple protocols.
RabbitMQ review

Questions people ask

Is PostgreSQL or RabbitMQ better?
Neither clearly leads. PostgreSQL starts at Free and RabbitMQ at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, PostgreSQL or RabbitMQ?
PostgreSQL starts at Free and RabbitMQ at Free.
Does PostgreSQL or RabbitMQ run on more platforms?
PostgreSQL runs on Linux, Windows, macOS, BSD, Unix. RabbitMQ runs on Linux, macOS, Windows, Docker, Kubernetes.
Can I use PostgreSQL for free?
Both have a free tier, so you can try either at no cost before committing.
What is PostgreSQL best used for?
PostgreSQL is most often used for transaction processing, data storage, application backend, reporting. Of those, transaction processing and data storage are not what RabbitMQ is typically brought in for.
What can PostgreSQL do that RabbitMQ cannot?
PostgreSQL covers ACID Compliance, JSON/JSONB Support, Full-text Search, Extensibility. RabbitMQ covers Flexible routing, Multiple protocols, Management UI, Clustering and mirroring.

Answered from the vendors’ own pages

PostgreSQL: Is PostgreSQL completely free?

Yes. PostgreSQL is completely free and open source with no licensing fees or restrictions on use.

Source
RabbitMQ: Is RabbitMQ free?

Yes, open source with no licence fee. Broadcom sells commercial support.

PostgreSQL: What platforms does PostgreSQL run on?

PostgreSQL runs on all major operating systems including Linux, Windows, macOS, BSD, and commercial Unix variants, and has been proven highly scalable managing terabytes to petabytes of data.

Source
RabbitMQ: RabbitMQ or Kafka?

RabbitMQ is a message broker: simpler to run and better at flexible routing and work queues. Kafka is a replayable event log built for very high throughput streaming, and much heavier to operate.

PostgreSQL: What procedural languages are supported?

PostgreSQL supports stored functions and procedures in multiple languages including PL/pgSQL, Perl, Python, Tcl, Java, JavaScript, R, and Rust.

Source
RabbitMQ: Can RabbitMQ replay messages?

Not in the way Kafka can. Messages are removed once acknowledged, so rebuilding state from history is not the model.

PostgreSQL: What is ACID compliance in PostgreSQL?

PostgreSQL has been ACID-compliant since 2001, ensuring data integrity through atomicity, consistency, isolation, and durability guarantees for all transactions.

Source
PostgreSQL: Does PostgreSQL support JSON data?

Yes. PostgreSQL supports JSON and JSONB data types for storing and querying JSON documents, along with XML and other document formats.

Source
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