Just try to create a ODBC connection from DS & check if connection is sucessful.
If the connection is successful, create a workflow with Oracle DB connector and run it to check if it is working.
Also,
check if there are any hotfixes for Oracle19c support for DS 9.1 at = https://www.ibm.com/support/fixcentral
In 'Product selector' TAB, type = IBM InfoSphere Information Server
& then select your version from the drop down menu in next column.
Regards,
Amey.
#DataIntegration#DataStage#Support#SupportMigration