It looks like Excel uses the XMLA DISCOVER command for MDSCHEMA_MEASUREGROUPS to populate the "Show fields" dropdown. For a Tabular model, this command seems to always return all the tables in a model - regardless of whether a table is hidden or not, or whether it contain any measures or not.
Logically, a table should not be reported as a measure group if it does not contain any (visible) measures. But to prevent breaking changes, I would suggest a new property or perhaps an annotation on the table, which would prevent that table from being reported in the DISCOVER command (or corresponding DMV) for MDSCHEMA_MEASUREGROUPS.
Tables should be prioritised, in my opinion, as it is relatively easy to access data in files using a custom SSIS script component. But with an SSIS connector that could read data directly from an ADLA table, we would no longer need to end all our U-SQL scripts with an OUTPUT statement, which would be a huge improvement!
It’s on the backlog, just need to get to it…
This work necessary to support this is in progress.
Any update on this?
On a related note, we need the ability to dynamically TRUNCATE partitions, for example by specifying a rowset with a list of partition buckets to be truncated.