Comparing Citus Database Options

Citus is an extension to Postgres that distributes your data & your queries across multiple nodes. Available as open source, as a fully-managed database as a service, and as enterprise software you can run anywhere.

Citus Distributed Database Features:	Citus Community Open Source	Citus Cloud Database as a Service	Citus Enterprise Enterprise Software

Relational database semantics Citus is Postgres, which means we offer relational database features like ACID transactions, joins, foreign key constraints, and SQL coverage.
Horizontal scalability & sharding Citus is an extension to Postgres that enables you to scale out Postgres across multiple nodes, giving your Postgres database a much larger memory, compute, and disk footprint than on a single-node. And increasing performance in a big way. At Citus, we like to say that we make sharding simple.
Distributed SQL engine Distributed query planner and executor that parallelizes queries across shards, enabling massive parallelism and efficient resource utilization.
Extension to Postgres Citus is not a fork, rather we use PostgreSQL’s extension APIs to scale out. We give you trusted, familiar Postgres.
Rich data types & Postgres extensions PostgreSQL and Citus support 40+ data types, including semi-structured data types and JSONB. Popular Postgres extensions frequently used with Citus include HyperLogLog (HLL), PostGIS, TopN, hstore, pg stat statements, dblink, plpgsql, uuid ossp, ltree, & more.
3 ways to get Citus Citus is available as open source, as a fully-managed database as a service, and as enterprise software you can run anywhere.
Compatible with popular programming languages, includes Rails & Django support Works with Ruby, Python, Java, Node.js, Javascript, Go, C++. And to make it easy to migrate your multi-tenant Rails and Django apps to Citus, we’ve created PostgreSQL libraries: activerecord-multi-tenant gem on Rails, and django-multitenant library for Django.
Distributed transactions
Probabilistic distincts (sketch algorithms)
Fine-grained access controls
High Availability & Streaming Replication Citus Cloud includes fully automated HA that is managed by the team at Citus; Citus Enterprise includes software features & instructions to implement HA on-prem.
Tenant isolation Multi-tenant SaaS applications sometimes need to isolate the shards for a large customer to ensure that the large customer gets the resources they need and doesn’t negatively impact performance for everyone else. Hence: tenant isolation.
Citus Support & SLA
Zero-downtime shard rebalancer When adding nodes to a Citus cluster, the zero-downtime shard rebalancer enables you to redistribute shards across old and new nodes to better balance the data distribution and the performance of your Citus database.
Simple provisioning & easy to scale out In Citus Cloud, you can setup a cluster in just a few clicks; adding more nodes & increasing memory, compute, and disk is as simple as dragging a slider
Fully-managed database as a service Citus Cloud is run by a team with decades of collective experience managing millions of Postgres databases in the cloud. Hosted on AWS and available in most AWS regions, Citus Cloud includes automated backups, high availability, point in time recovery, automated health checks, automated monitoring, forks, & followers.
Citus Cloud security suite Includes HIPAA, 2FA, encryption at rest and in flight, role-based, fine-grained access controls, VPC peering, IP whitelisting, and of course continual review of security vulnerabilities.