In general, Denodo follows the introspection method defined by the underlying JDBC driver.
If I face this issue I would perform the below checks:
* Ensure that the user account mentioned in the data source has enough privileges to list all the schemas and tables.
* Try connecting to the MYSQL source in an external JDBC client like Dbvisualizer with the same user account that is used in the Data Source in Denodo and try listing the schemas and executing the tables of the source.
* If above test works then I will try to create a base view using the [create from query](https://community.denodo.com/kb/en/view/document/Using%20the%20Create%20Base%20View%20From%20Query%20Option) option in the Denodo.
If you still need further assistance and if you are a valid support user, you can raise a [Support Case](https://support.denodo.com/cases/add), for further assistance from the Denodo Team
Hope this helps!