Secondary Datasource Sucessfully validated after Upgrade to 16.3 but none of the tables are accessible

Have you checked that the driver for your secondary data source matches the required version for 16.3? Is the Data source configured via the Admin Console or ds-xml? Can you access the database outside of Appian using the same credentials? Is there any error in the logs? If so, please provide a extract?

We figure out what is causing the problem but the solution has not been identified. Appian 16.3 converts username and table names to lower case and double quotes it, it is oracle case sensitivity problem. We used to use custom.teneo.properties now I am not sure what the solution is.

I'm surprised to hear you still have the property for "custom.teneo.properties" as it was used around Appian version 6.6 and was resolved. I would recommend cloning the secondary data source and seeing it you can correct the names from the Oracle side then remap in Appian to the cloned source? Alternatively, create a new datasource, remap all datatypes to it then via the database, merge the context from the existing ds with the issue.