Top 13 Cloud Database Engines

Cloud Database Engines - database management systems that run on a cloud computing platforms with high load.
MongoDB is an open-source document database, and the leading NoSQL database. Written in C++, MongoDB features: Document-Oriented Storage, Full Index Support, Replication & High Availability, Auto-Sharding, Querying, Fast In-Place Updates, Map/Reduce and others.
Redis is an open source, BSD licensed, advanced key-value cache and store. It is often referred to as a data structure server since keys can contain strings, hashes, lists, sets, sorted sets, bitmaps and hyperloglogs.
MySQL is the world's most popular open source database. Whether you are a fast growing web property, technology ISV or large enterprise, MySQL can cost-effectively help you deliver high performance, scalable database applications.
Oracle Database introduces a new multitenant architecture that makes it easy to consolidate many databases quickly and manage them as a cloud service. It also includes in-memory data processing capabilities delivering breakthrough analytical performance. Additional database innovations deliver new levels of efficiency, performance, security, and availability. Oracle Database enables customers to plug into the cloud and power the real-time enterprise.
SQL Server enables customers to build mission-critical applications and Big Data solutions using high-performance, in-memory technology across OLTP, data warehousing, business intelligence and analytics workloads without having to buy expensive add-ons or high-end appliances. SQL Server uses a common set of tools to deploy and manage databases both on-premises and in the cloud, which makes it easier for customers to take advantage of the cloud with existing skills.
PostgreSQL is a powerful, open source object-relational database system. It has more than 15 years of active development and a proven architecture that has earned it a strong reputation for reliability, data integrity, and correctness. It runs on all major operating systems
Riak is an open source, distributed database. Riak is is designed to store data and serve requests predictably and quickly, even during peak times. Riak replicates and retrieves data intelligently, making it available for read and write operations even in failure conditions. Riak is fault-tolerant so you can lose access to nodes due to network partition or hardware failure and never lose data.
FoundationDB is multi-model, meaning you can store many types data all in a single database. All data is safely stored, distributed, and replicated in the Key-Value Store component, and new functionality, like our SQL Layer, is layered on top of its simple API.
One of the most popular database servers. Made by the original developers of MySQL. Guaranteed to stay open source.
DocumentDB is a highly scalable, NoSQL document database service offering rich query and transactional processing over a schema-free JSON data model. The service helps you quickly build, grow, and scale applications that run in the cloud when predictable throughput, low latency, and flexible queries are key.
  on Live Enterprise
Google Cloud Bigtable offers you a fast, fully managed, massively scalable NoSQL database service that's ideal for web, mobile, and Internet of Things applications requiring terabytes to petabytes of data. Unlike comparable market offerings, Cloud Bigtable doesn't require you to sacrifice speed, scale, or cost efficiency when your applications grow. Cloud Bigtable has been battle-tested at Google for more than 10 years—it's the database driving major applications such as Google Analytics and Gmail.
Quickly & Easily Deploy your Database with Compose. Compose deployments scale seamlessly as your data grows. Spend more time on your data model, less time capacity planning. This is how everyone should run databases.
PipelineDB is an open-source relational database that runs SQL queries continuously on streams, incrementally storing results in tables.

Latest news about Cloud Database Engines

2016. Microsoft SQL Server is available on Linux

SQL Server, Microsoft’s flagship relational database product, is now available on Linux in the form of an early private preview, with a full launch planned for mid-2017. This announcement fits into Microsoft’s overall emphasis on hybrid deployments. Microsoft already runs Linux in its cloud and recently announced a major partnership with Red Hat, for example. If it wants SQL Server to remain relevant, it needs to bring it to more platforms — including those that it previously regarded as competitors. On Linux, after all, products like MySQL, MariaDB and PostgreSQL are also vying for a very similar slice of the market.

2016. MariaDB developer raises $9M

MariaDB Corporation — the startup formerly known as SkySQL and building for-profit solutions on the SQL fork managed by the MariaDB foundation — has raised another $9 million in funding . The funding brings the total raised by MariaDB to just over $40 million. This latest cash injection will be used for marketing, to launch new products, and to help further shift the startup’s center of gravity to the U.S. market from its home country of Finland. The foundation notes that use of MariaDB has been growing at a steady pace since being founded in October 2011 (although a rather steep decline in the last two months suggests perhaps that a huge customer has migrated?). This points to an opportunity for MariaDB the startup to monetise that usage with its commercial implementations.

2016. PipelineDB launched Enterprise version of its streaming SQL database

PipelineDB announced the release of PipelineDB Enterprise - the first commercial version of the open-source product that built on a new way of looking at SQL databases - thinking about streams of data rather than data at rest in big silos. The company makes a big bet on this type of database and so far it appears to be working quite well. While they don’t have exact numbers, he pegs the number of installations in the low thousands with deployments running all day long in the low hundreds. The commercial product has always been on the drawing board, but they are releasing it now because large enterprise customers are demanding additional features such as replication and failover hardware nodes for high availability, which is essential for companies using the product for mission critical purposes.

2015. MongoDB broadened its reach to business analysts

MongoDB, which is now the fourth most popular database in the world, just raised the ante with the release of MongoDB 3.2. Business analysts who are used to working with legacy databases can now work with MongoDB in much the same way via the newly introduced MongoDB for Connector for BI. The learning curve that once made it difficult has now been eliminated. MongoDB is also releasing a new product, Compass, which brings the kind of graphical tools that DBAs and development teams have come to rely on in relational databases available. Until now, MongoDB pros have had to forgo visibility for flexibility, but no more. Now they can quickly and securely explore their databases, visually construct queries, inspect records and make decisions about their deployments.

2015. IBM buys database-as-a-service provider Compose

IBM has acquired Compose, the database-as-a-service startup originally known as MongoHQ.  IBM spokesperson told that Compose will continue to operate as usual after the acquisition closes and that current users will not be impacted by this change. Compose says about 3,600 companies currently use its services and that its users, which span industries from retail to IoT and marketing services, have spun up over 100,000 databases so far. While Compose started out as a MongoDB database specialist, the company now offers services around MongoDB, Elasticsearch, RethinkDB, Redis and PostgreSQL. The overall idea behind Compose is to allow mobile and web developers to create their apps without having to worry about their database backends.