Gartner defines a DBMS as a complete software system used to define, create, manage, update and query a database. A database is an organized collection of data that may be in multiple formats and may be stored in some form of storage medium (which may include hard-disk drives, flash memory, solid-state drives and/or DRAM). Additionally, according to Gartner's definition, DBMSs provide interfaces to independent programs and tools that both support, and govern the performance of, a variety of concurrent workload types. There is no presupposition that DBMSs must support the relational model or that they must support the full set of possible data types in use today. Furthermore, we do not stipulate that the DBMS must be a closed-source product; we include commercially supported open-source DBMS products in this market. Operational DBMSs must, however, include functionality to support backup and recovery, and have some form of transaction durability — although the atomicity, consistency, isolation and durability (ACID) model is not a requirement.
Oracle, IBM, Amazon AWS, Microsoft, MongoDB, SAP, DataStax (Cassandra), EnterpriseDB, Redis, MarkLogic & InterSystems are in the leaders quadrant of ‘Magic Quadrant for Operational Database Management Systems 2015’.