The error "Database does not support block update" occurs when the underlying cache database does not support batch insert or update.
In Virtual DataPort, when a view is cached, the rows of the view are inserted in batches based on the** Batch Insert Size** provided in the cache configuration. This batch insert may not be supported by Exasol database.
Since batch insert facilitates better performance, I would use the database which supports batch insert or update for caching in Virtual DataPort.
You could refer [Bulk Data Load](https://community.denodo.com/docs/html/browse/6.0/vdp/administration/bulk_data_load/bulk_data_load) section of Virtual DataPort Administration Guide for more information.
Hope this helps !!