While pulling a table from Oracle database Power Query auto adds multiple list and table columns

Hi,

I just experienced a strange behavior of Power BI Desktop Query Editor.

When I pull a database table using select * from, I get the entire table correctly loaded (160 columns).

However when I use Import table functionality, Query Editor adds multiple columns to the original 160 (+40 in my case...), which seem to be list and table columns.

I have the option to unpivot any of them.

When I tried unpivot on a list column it folded out into two additional columns: 

(1) Attribute

(2) Value - this one is a record....

Can someone explain what is going on?

Thank you

Balazs