Oracle Database 23c Free – Developer Release is a new, free offering of the coming 23c Oracle database (the next Long Term Support release coming in the next 12 months). It can be downloaded straight from the Internet with 1 click, enabling simple and fast access or from Docker Hub (more on that later).
As a converged database (since the 2000s), it's not anymore just a relational database! You can throw at it JSON, XML, Spatial, Property Graph, RDF, Machine Learning models, etc. and you'll be able to store these data and of course process them, including mixing them using SQL of course as well as NoSQL-oriented APIs: REST, MongoDB API, SODA, etc.
Oracle Database 23c Free – Developer Release is built-in upward compatibility with Oracle Database Enterprise Edition and Oracle Database cloud services ensures that users can move to any other Oracle Database offering anytime.
JSON Relational Duality: you can build applications in either relational or JSON paradigms with a single source of truth and benefit from the strengths of both, relational and document models. Data is held once but can be accessed, written, and modified with either approach. You benefit from the best of both JSON and relational models, including ACID-compliant transactions and concurrency controls, which means you no longer have to make tradeoffs between complex object-relational mappings or data inconsistency issues.
JSON Schema: you can now ensure and validate JSON document structures via industry-standard JSON Schemas, enabling the confident and reliable use of the JSON data format.
Operational Property Graphs: you can now build both transactional and analytical property graph applications with Oracle database, using its industry-leading, new ISO SQL:2023 standard property graph queries support, including running graph analytics on top of relational and JSON data.
Oracle Kafka APIs: Kafka applications can now run against Oracle database Transactional Event Queues with minimal code changes enabling much more robust microservices built using transactional events that perform event operations and database changes in a single atomic transaction.
Application Usage Domains: The new domain construct can act as lightweight type modifiers that centrally document intended data usage, extending and drastically improving SQL standard domains. This allows you to better understand how the data is used and improves overall data quality, without the complexity and incompatibility of usage-specific data types or user-defined types.
Application Usage Annotations: Database metadata can now be stored directly alongside the data with the new Annotation mechanism inside the Oracle database. You can annotate common data model attributes for tables, columns, views, indexes, etc., providing a central, lightweight, declarative facility to register and exchange usage properties across applications. Storing the metadata along with the data guarantees consistency and universal accessibility to any user or application that uses the data.
There is of course much more to discover such as all the SQL enhancements: SELECT without DUAL table, GROUP BY alias or position, Table Value Constructor, IF [NOT] EXISTS clause, etc. inside the New Features Guide.
Finally, if you need help, there is a community forum to support you.