Commercial Microsoft SQL Server Alternatives

IBM DB2 is an enterpise-class relational database management system. IBM DB2 is built for mission critical workloads and provides advanced features like adaptive workload management, time travel query, query federation, in-database AI, row/column access control, auditing, and support for JSON, XML, and geospatial data sets. IBM DB2 is used by fortune-500 companies like Bank of America and JPMorgan Chase.

Cockroach is a distributed key/value datastore that allow you to build, scale and manage modern, data-intensive applications. The database delivers distributed SQL by combining the familiarity of relational data with limitless, elastic cloud scale and bulletproof resilience. Correct data is a must for mission-critical and even the most common applications. CockroachDB provides guaranteed ACID compliant transactions, allowing you to fully trust your data.

MemSQL is a free and open-source all-in-one relation database management system. The database lends itself for operational analytics and AI/ML-powered applications that requires fast data ingest, high performance queries and elastic scaling. MemSQL supports ANSI SQL and blended workloads, commonly referred to as translytical, HTAP, HOAP, and ATP workloads. The developer MemSQL Inc, also provides commercially hosted version of the database called MemSQL Helios, a cloud database-as-a-service.

Couchbase, originally known as Membase is an award-winning, open-source, distributed multi-model NoSQL and document-oriented cloud database. It is designed and optimized for interactive applications and may serve many concurrent users by creating, storing, retrieving, aggregating, manipulating and presenting data. Couchbase delivers unmatched versatility, performance, scalability, and financial value across cloud, on-premises, hybrid, distributed cloud, and edge computing deployments.

Azure Cosmos DB is a non-relational NoSQL database trusted by leading enterprises globally. With Azure Cosmos DB you can run No-ETL analytics over real-time operational data and run near-real time analytics and AI on the operational data within your NoSQL database, to reduce time to insight.

Amazon DynamoDB is a key-value and document database that delivers single-digit millisecond performance at any scale. The database is fully managed, multiregion, multimaster, and durable with built-in security, backup and restore, and in-memory caching for enterprise-scale applications. Amazon DynamoDB is part of Amazon Web Services and integrates well with other cloud-based AWS products.

NuoDB is a distributed relational database management system utilizing SQL. The database is architected to meet the rapidly evolving demands of today's enterprises, NuoDB can be used to deploy on-premise, extend to the cloud, scale on demand, eliminate downtime and reduce total cost of ownership. All while maintaining SQL compatibility and a workflow that most developers are familiar with.

CouchDB is a free and open-source document-oriented NoSQL database developed by the Apache Foundation. The database is written and implemented in the language Erlang and provides the use of multiple formats and protocols to store, transfer, and process data. With CouchDB you query data with JavaScript using MapReduce, and HTTP for an API. Which can be done across multiple distributed CouchDB instances as the database has the ability to synchronize multiple copies of the same database, across servers.

DeepDB also known as DeepSQL is a proprietary MySQL storage engine designed for OLAP and OLTP workloads. It was designed to be an alternative to the InnoDB storage engine for MySQL.