I've configured drill to use an JDBC storage plugin. My connection string is for an Oracle database. I have included the Oracle JDBC driver to my drill deployment.
The connection is established correctly. However the storage plugin fails to retrieve the schema of the database.
The JDBC API provides two ways to get metadata about the database: getSchemas() and getCatalogs(). Depending on the database vendor one of those calls will return the information. The storage plugin correctly tries both calls. However I believe there is an issue when using Oracle.
The JDBC API claims that getSchemas() returns a set of two columns "table schema" and "table catalog" but in reality it just returns "table schema" as a first column of the result set. I believe this to be a bug. Has anyone tested the JDBC storage plugin against an Oracle DB and successfully retrieved the list of schema and tables?
This article explains in details the issue in retrieving schema information using JDBC. https://www.wisdomjobs.com/e-university/jdbc-tutorial-278/what-are-catalogs-and-schemas-1147.html