Citus Community

The Citus open source extension to PostgreSQL distributes your data and queries across multiple nodes in a cluster so your application can scale and your queries are fast. Citus makes database sharding simple.


Looking for the Citus open source repo? Find Citus on GitHub.

Open Source Extension to an Open Source Database

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Power of Postgres

We get that you trust Postgres. So we built Citus as an extension to Postgres. And we built Citus to scale out. With Citus, you get to leverage all your Postgres expertise, use your familiar SQL toolset, and scale out your database.

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Not a Fork

Our Citus open source database is an extension to Postgres. Not a fork. So it’s easy for us to keep Citus in sync with the latest releases of Postgres, and to stay current with all the innovations in the Postgres community.

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Run Anywhere

Because Citus is open source, you can avoid vendor lock-in. And because Citus is available as open source, as on-prem enterprise software, and in the cloud built into Microsoft Azure, you can run Citus anywhere.

Postgres is a Favorite Among Databases for Good Reason

All the Goodness of Postgres

Because we’ve implemented Citus as an extension to Postgres, you get trusted and familiar Postgres with Citus, complete with all the data types, operators and functions, extensions, and indexes in Postgres. Plus the reliability of Postgres and all of the ongoing innovation in the Postgres community. Also, JSONB.

Postgres Tooling & Ecosystem

The Postgres ecosystem of tools, extensions, and libraries is vast. One of the reasons Citus is popular is because Citus is an extension to Postgres: therefore you get to leverage your Postgres expertise and use all of your familiar Postgres tools.

Relational Database Semantics

Citus is an extension to Postgres, which means we offer relational database features like ACID transactions, joins, foreign key constraints, and SQL.

Streaming Replication

The streaming replication feature in Postgres can be used to setup High Availability secondary nodes and failover capabilities for Citus.

Who Says You Can’t Scale Out A Relational Database?

Packaged as a Postgres Extension

Because Citus is an extension to Postgres and not a fork, Citus can easily stay current with the latest releases of Postgres, allowing you to benefit from all of the latest innovations in Postgres.

Horizontal Scale via Sharding

Citus shards your Postgres database across multiple nodes to give your application more memory, compute, and disk storage. Which gives you massive parallelism, high performance, and a way to keep scaling as your application grows.

Distributing SQL Queries & Transactions for Speed and Scale

Distributed Query Engine

Citus takes an incoming SQL query, plans the query for parallel execution, and pushes down the parallel computations to the nodes in the database cluster. As you add new nodes, Citus automatically distributes queries to leverage all the memory and cpu cores available.

Dynamic Query Executors

Multi-tenant and analytic workloads introduce different trade-offs in a distributed database. Citus comes built-in with three dynamic executors, each optimized for a different workload, and Citus intelligently determines which executor to use, based on the query.

Distributed Transactions

Citus provides full SQL transactions across shards and nodes, making it easier than ever to migrate applications onto Citus.

Cross-Tenant Query Support

Because Citus can parallelize query fragments across multiple nodes cluster, you can run powerful cross-shard queries across all of your customer data quickly and easily.

Massive Parallelism

As a distributed database that can scale out Postgres to hundreds of nodes, Citus gives you unparalleled parallelism and performance across billions of records. By allowing you to perform scale-out analytics across your entire data set, you can provide new value to your customers where not possible before.

Monitoring & Management Features in Citus


To analyze and retain your Postgres and Citus logs over time, logs can be transmitted to log management apps such as Splunk, Loggly, Papertrail, Sumo Logic, and Logentries.

Monitoring Metrics

Citus utilities can be used to query Citus table and relation sizes. The popular pg_stat_statements gives visibility into statistics about queries that are running on the database. And many customers integrate their favorite monitoring tools with Postgres and Citus.

Distributed Explain

The Postgres EXPLAIN feature creates a query plan for each query it receives and is invaluable in optimizing performance. In Citus, we’ve created a distributed EXPLAIN feature that performs the same function in the context of a distributed database.

Rich Data Types & Extensions


PostgreSQL and Citus support 40+ data types, including semi-structured data types and JSONB. Many developers celebrate the JSONB support in Postgres database as a way to store blobs in the database in a way that enables document store workflows.

HyperLogLog (HLL)

HLL is an algorithm for the count-distinct problem and can approximate the number of distinct elements in a set. With sketch algorithms for probabilistic distincts such as HLL, you can provide deeper analytics in real-time across petabytes of data.


PostGIS is an extension to Postgres that adds support for geographical objects to Postgres, allowing location queries to be run in SQL. Open source, freely available, and works with Citus.


TopN is a new, open source PostgreSQL extension. Created by Citus Data, TopN can be used to calculate the most frequently occurring values in a column, and is part of the class of probabilistic distinct algorithms called sketch algorithms.

Full Text Search

Full text search in Postgres enables you to search documents, parts of documents, and semi-structured data using regular expressions and text search from within your Citus database.

Run Anywhere with Citus: On-Prem, in the Cloud, and Open Source

Open Source

We’re on a mission to make it so you never have to worry about scaling your database again. And by database, we mean Postgres. Download the Citus extension to Postgres and get started scaling out today.


The Citus Enterprise software comes is the same as our open source offering with the addition of a few enterprise features and 24x7 Citus Support. The ideal cloud-ready database to scale out Postgres in an on-prem environment.

In the Cloud

Convenience trumps all, and many customers say they would rather focus on their application, not their database. So we make Citus available in the cloud, built into Azure Database for PostgreSQL, a fully-managed database as a service.

The Citus open source extension to Postgres, deployed on a 20-node Citus cluster with SSDs, has enabled us to achieve phenomenal I/O parallelism and I/O throughput. We have been able to dramatically increase performance and also to cut costs. Citus has been a competitive and operational game-changer for our business.

Scott Milliken, Founder & CEO of MixRank

Are You Ready to Scale Out Postgres with Citus?

Prefer a cloud database? Learn about Citus on Azure

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