Oracle RDBMS is a widely-used proprietary DBMS released by Oracle Corporation. The most recent version released was 18c; version 18.3 was released in July 2018. It supports a multi-model storage paradigm, allowing for JSON, key-value, XML, and graph models in addition to the traditional relational model.
In 1977, Larry Ellison, Robert Miner, and Ed Oates founded Software Development Laboratories, which was hired by the United States Central Intelligence Agency (CIA) in order to write a new database system based upon SQL. This system came to be known as Oracle. The company changed its name to Relational Software, Inc. in 1979 and then to Oracle Systems Corporation not long thereafter, in 1982.
Oracle employs MVCC for concurrency control.
Oracle supports isolation levels of read committed as well as serializable, defaulting with the latter. There is an additional mode available, "read only", which is not part of the SQL standard.
Stored procedures are supported by Oracle.
Oracle supports a variety of data models for storage within its system.