Incremental cache mode is used in scenarios where the data is not physically deleted, it's just marked as ‘deleted’ or ‘invalid’. Main benefit is that there is no need to retrieve the full result set once the initial cache load is done, only the modified rows are retrieved. These scenarios are typically found in data warehousing/reporting use cases.
In Incremental load a row which is not in the source (i.e. deleted in source) but in the cache, will be returned from the cache. So, the view will return the deleted rows until the cache of this view is invalidated and cached again. You can take a look at [Incremental mode](https://community.denodo.com/docs/html/browse/7.0/vdp/administration/cache_module/cache_modes/incremental_mode) Virtual DataPort guide to know more.
I would go for Partial cache or Full Cache (Without Incremental mode) in case where the rows would be physically deleted. You can also take a look at [Cache Maintenance](https://community.denodo.com/docs/html/browse/7.0/vdp/administration/cache_module/cache_maintenance_task/cache_maintenance_task#cache-maintenance-task) and [CLEAN_CACHE_DATABASE](https://community.denodo.com/docs/html/browse/7.0/vdp/vql/stored_procedures/predefined_stored_procedures/clean_cache_database) user guides for maintaining the cache.
Hope this helps!