Open-source Azure Database for PostgreSQL alternatives

PostgreSQL is a feature-rich object-relational database management system covering a large part of the SQL standard. Its feature set includes transactions, foreign keys, subqueries, triggers, and user-defined types and functions, and the distribution also contains C language bindings. This GitHub repository is only a mirror of the official git repository, written in C, and the metadata lists the license as Other.

The project does not use GitHub pull requests; contributors submit patches through the process described on the PostgreSQL wiki. Copyright and license terms are in the COPYRIGHT file, general documentation for each version is published on the project site, and build instructions explain how to compile the server from source. The latest releases of the software and related software are available from the PostgreSQL website. Many hosting providers offer managed PostgreSQL, but the project itself is software you install and operate.

Citus is an extension that transforms PostgreSQL into a distributed database so it can keep performing as data and traffic grow. Instead of replacing Postgres, it adds capabilities to it, and because it is an extension it works with recent PostgreSQL versions and the tools and extensions people already use.

Distributed tables are sharded across a cluster of nodes to pool CPU, memory, storage and I/O, while reference tables are replicated to every node for joins and foreign keys. A distributed query engine routes work to the right shards and runs SELECT, DML and other statements in parallel, columnar storage compresses data and speeds up scans, and queries can be sent to any node. More worker nodes can be added and shards rebalanced as data grows.

Typical uses include multi-tenant applications, real-time analytics, high-throughput transactional workloads and time-series or IoT data. Citus is written in C, licensed under AGPL-3.0 and described by its authors as fully open source, and it can start as a single node and scale out later. The project links a SIGMOD paper describing how it works.

YugabyteDB is a distributed SQL database that is compatible with PostgreSQL. It combines the relational features of traditional databases with the scale-out design of NoSQL systems, and is intended for cloud-native OLTP applications that need correct data and at least one of scalability, tolerance to failures or global distribution.

Its SQL layer, YSQL, reuses the PostgreSQL query layer and so supports most PostgreSQL features, including data types, stored procedures, triggers and extensions. Its transaction model follows the design of Google Spanner, using Raft consensus for replication and hybrid logical clocks for distributed ACID transactions, with snapshot, serializable and read committed isolation. Reads are strongly consistent by default and can be tuned to read from followers and replicas.

The database can be configured to withstand failures at the level of a disk, rack, node, zone, region or whole cloud, recovering on its own, and the topics mention multi-region, multi-cloud and Kubernetes deployments. The project is written mainly in C and C++, the repository lists its license as Other, and documentation covers architecture, roadmap and how to build applications.

CloudNativePG, often shortened to CNPG, is an open-source platform for running PostgreSQL databases on Kubernetes. Its core component is an operator that handles the whole operational lifecycle, from deployment to ongoing maintenance, in a way that fits GitOps-driven CI/CD automation.

It takes a Kubernetes-native approach to primary and standby cluster management. Rather than relying on external high-availability tools such as Patroni, repmgr or Stolon, the operator integrates directly with the Kubernetes API, and the status of a PostgreSQL cluster is exposed on the Cluster resource. It follows the operator pattern to reconcile the desired state, and application containers are immutable. Topics also list failover, switchover, replication, disaster recovery, a kubectl plugin, a Prometheus exporter and JSON logging.

CloudNativePG is a CNCF project written in Go and licensed under Apache-2.0, with a quickstart guide, governance policies, a list of adopters and pointers to commercial support. It is intended for Kubernetes administrators who want PostgreSQL managed as a native workload.

Neon is a serverless Postgres database platform that is open source. It separates storage from compute and replaces the PostgreSQL storage layer with one that distributes data across a cluster of nodes, which enables autoscaling, branching of databases in the style of code, and scaling down to zero.

A running Neon system is made up of compute nodes plus a dedicated storage engine. The compute nodes are stateless PostgreSQL instances backed by that engine, whose two main components are the Pageserver, a scalable storage backend for the compute nodes, and the Safekeepers, a redundant write-ahead-log service that keeps WAL durably until the Pageserver has processed it and uploaded it to cloud storage. Developer documentation describes the architecture in more detail.

The easiest way to try Neon is the hosted Neon Free Tier, connecting with psql, DBeaver or the online SQL editor. The project is also written in Rust and licensed under Apache-2.0 so you can compile and run it locally for experiments, with build instructions for Linux and macOS. It suits teams that want Postgres with branching for development workflows and elastic scaling.

Autobase is an internal database platform for PostgreSQL that brings the managed database experience of a cloud DBaaS onto infrastructure you control. You build and operate production-grade PostgreSQL clusters with high availability, and the tool aims to simplify deployment, reduce operating costs and make database management approachable even for teams without deep database expertise.

It automates deployment, failover, backups, restore, upgrades and scaling, with Patroni topics indicating a proven high-availability foundation, and offers a web interface written in TypeScript on top of automation scripts. The documentation includes an architecture overview. It is the successor to what was previously a PostgreSQL cluster automation project.

Autobase is MIT-licensed and self-hosted, running on your own servers, virtual machines or cloud accounts. It suits platform teams and companies that want managed-database convenience without paying for a hosted service, and that are ready to operate the underlying machines.