Open-source Azure SQL Database alternatives

MySQL is a widely used open-source relational database. This repository contains the MySQL Server source code along with MySQL Cluster, which the description presents as a real-time, open-source transactional database. Applications talk to it using SQL, and it is a common choice for web applications and embedded products.

The MySQL website describes several offerings built around the server: the Community Edition, with a published governance model and early access builds; MySQL Enterprise Edition for advanced features, management tools and technical support; MySQL HeatWave, a cloud service that combines transactions with analytics and machine learning; and MySQL Cluster CGE. A program for OEM and ISV vendors covers embedding the database in other products.

The server is written in C++ and distributed under licenses detailed in the repository. Organizations can run the Community Edition on their own infrastructure, buy a commercial edition from Oracle, which owns the project, or use a managed cloud offering. Documentation, downloads and a developer zone are available on mysql.com.

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.

MariaDB Server is an open-source relational database built by a global community with the MariaDB Foundation and MariaDB plc. It started out as a MySQL fork driven by the people who created MySQL, keeps a high degree of MySQL compatibility, and is described as a straightforward migration target for existing MySQL deployments.

Since then it has gained its own capabilities. A native VECTOR data type with approximate nearest-neighbour HNSW indexing has been available since version 11.8. Pluggable storage engines include InnoDB, Aria and MyRocks, plus ColumnStore (analytics), Spider (sharding) and S3 (archiving). Replication options include async, semi-sync and parallel modes using global transaction IDs, and Galera provides synchronous multi-primary clustering. On the SQL side it offers common table expressions, window functions, temporal tables with system versioning, sequences and a range of JSON functions.

It also offers an Oracle SQL mode with PL/SQL-style routines, GIS data types and full-text indexing, and security features such as role-based access control, pluggable authentication, data-at-rest encryption and TLS. MariaDB is written in C++ and licensed under GPL-2.0, and you run it on your own servers or in the cloud.

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.