Bug in unity catalog registering external database that is case sensitive

[AurelioGesino]

I successfully registered in my Unity Catalog an external Database ```dwcore``` that is hosted on SQL server.
I first added the connection in "External Data": tested the connection and it was successful.
I then added the database on top: tested the connection and it was successful.

Then on the unity catalog explorer I checked I saw that the tables can be seen under the "dbo" schema.
I can see all table listed on the tree on the left.
But then, if I try to query any table, the table is not found by Spark.

I tested with another postgres database and everything works like a charm.
I think the issue is this: my SQL server table names are case sensitive.

So for example I have a table "AllAlarms" that in the external catalog gets registered all lowercase.
It becomes "allalarms".
So when I try to query the table in the unity catalog the real SQL table does not get resolved, because I'm querying with a lowercase name when it should have been registered registering its real case.
I tried as well to set Spark to be 

spark.sql.caseSensitive', True

but that does not help, because the error occurs when the table is registered in the catalog.

So I think this is a bug with Databricks.

[AurelioGesino]

Hi Kaniz, thank you for your feedback.
Databases that I have to link cannot be changed, other teams and products rely on those databases as well, this change would be disruptive.

I think this is a limitation in the unity catalog behaviour, as it should take in account that external databases could have a case sensitive collation, either:

- keeping the name of the tables as they are, leaving up to the user to deal with case issues for external tables.
- remapping that internally and hide it to the user
- providing some API where to hook on in the database registration, or perform it programmatically.

So I'll open up a ticket support for it.

Thank you