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Oracle Database 21c, the new release of the longtime industry leading RDBMS, is currently available in the Oracle Cloud, where it can be deployed as a Virtual Machine DB System (for clusters and single instance) or a Bare Metal DB System (single instance). It’s also available in the Autonomous Database Free Tier Service, with limited storage and CPU capacity. It will be available more broadly later this year, including on-premises.
While Oracle Database 20c was scheduled for release in 2020, that release was cancelled because of the COVID-19 pandemic and its effect on customer IT departments. All of the features planned for 20c were rolled into 21c.
There are several notable points to be made about Oracle Database 21c. It can serve as a transactional, analysis, or enterprise database, and tune itself for its usage. It supports relational, graph, spatial, text, OLAP, XML, and JSON data. It has in-database training of machine learning models that includes AutoML, and that training can take advantage of the extra CPUs in storage servers on Exadata hardware. Speaking of Exadata hardware, Oracle Database 21c takes full advantage of its Octane persistent memory, and the Autonomous Database feature uses Exadata to automate index creation.
For analysis, Oracle Database 21c can automatically configure which columns to place in memory, can perform SIMD vectorized hash joins, and can complete hybrid scans against in-memory columns and on-disk row stores. For in-database programming, Oracle Database 21c adds support for JavaScript, along with interfaces between JavaScript and Oracle Database types, SQL, and PL/SQL stored procedures.
Oracle claims high performance for all of its converged data types, even compared against databases specialized for JSON documents or graphs. The hard benchmark numbers for Oracle Database 21c are not yet available, however.
Oracle Database history
Oracle Database 21c is the result of four decades of development. Oracle Database was the first commercial SQL-based relational database (1979), implemented based on a published IBM specification. (IBM held off releasing its own relational database, DB2, to avoid cannibalizing sales of its hierarchical database, IMS.)
Briefly, Oracle Version 3 (1983) was a rewrite in portable C, to run on mainframes, minicomputers, and personal computers. Version 6 had enhancements to disk I/O, row locking, scalability, and backup and recovery. Oracle7 (1992) introduced PL/SQL...