History of Oracle Database version releases (1979 to 2021)

Oracle Database has evolved significantly over the years with numerous major releases, each introducing new features and improvements. Here's a brief overview of some of the major Oracle Database versions: 

 * *Oracle V2* (1979): The first commercially available version of Oracle, which ran on PDP-11 computers. 

* *Oracle V3* (1983): Added support for concurrency control, transaction management, and backup and recovery. 

* *Oracle V4* (1984): Introduced the first SQL-based query language and support for client-server architecture. 

* *Oracle V5* (1985): Improved performance, scalability, and added support for distributed databases. 

* *Oracle V6* (1988): Added row-level locking, multi-threaded server architecture, and improved security features. 

* *Oracle 7* (1992): Added support for stored procedures, triggers, and the PL/SQL programming language. 

* *Oracle 8* (1997): Improved object-relational support, introduced Java integration, and added advanced replication and partitioning features. 

* *Oracle 8i* (1999): Focused on internet integration and added support for XML and advanced queuing. 

* *Oracle 9i* (2001): Enhanced database management with automatic undo management, Oracle Real Application Clusters (RAC), and flashback query. 

* *Oracle 10g* (2003): Focused on grid computing, introduced Automatic Storage Management (ASM), and added support for regular expressions and XML DB. 

* *Oracle 11g* (2007): Enhanced security, performance, and manageability with features like Data Vault, Database Replay, and Real Application Testing. 

* *Oracle 12c* (2013): Introduced multi-tenant architecture, improved database consolidation, and added in-memory database capabilities. 

* *Oracle 18c* (2018): Focused on automation, security, and performance with features like Autonomous Database, Oracle Blockchain Cloud Service, and improved SQL tuning. 

* *Oracle 19c* (2019): Introduced automated indexing, real-time statistics, and improvements to Oracle Active Data Guard. 

* *Oracle 21c* (2021): Enhanced security, performance, and developer productivity with features like Blockchain Tables, AutoML, and improved JSON support. Each new Oracle Database version has brought improvements in scalability, security, and performance, making Oracle one of the leading database management systems in the industry.