When it comes to extracting metadata from different systems, it can become very complex as each system has its own way to store and offer metadata. Often data store system type offer a way to access the data via JDBC, but JDBC drivers functionality implementation may vary and not all function necessary for metadata extraction are always implmented.
The EDC JDBC scanner expect a certain number of functions to be implemented and those needs to be in a certain so that metadata can be extracted in bulk (use of getColumns method without specifying table name for example)
In order to workaround some limitation of certain JDBC drivers, there is a possibility to extract the metadata by using the JDBC driver available feature and bring the extracted metadata into the catalog via custom scanner.
Below is a link to an example of such metadata extractor that has been tested for Denodo.
this can easily be extended to other systems that are not yet ceritified with EDC such as AWS Athena, Alibaba Max Compute, etc. by providing the right JDBC driver and understanding what JDBC method is available with the driver.