Abstract: Modern web applications, as a necessity, require fast, efficient, and accurate data exchange, which all participants in communication can uniformly interpret. Consistency in interpreting exchanged data can be achieved using text, self-describing and platform-independent file formats such as XML and, recently, the even more popular JSON. JSON represents a common model for NoSQL databases. Also, it has been supported for years in relational databases from leading manufacturers, such as Oracle. This paper systematises, analyses, and compares the functionalities for working with JSON across different versions of Oracle DBMS, starting with version 12c R1, which introduced support for native JSON, concluding with the recently introduced version. For selected use cases, experimental tests were performed, which demonstrated the impact on performance achieved by the supported JSON functionalities from version 12c R1 to 19c of Oracle relational database management systems (DBMSs).