This is about Oracle database. There is a view like {ALL|DBA|USER}_TAB_COLUMNS which can be used to extract a list of columns for a given table. It has its counterpart ending with cols instead of columns. What a nice shortcut, isn't it?

Well, it is not just a synonym. Oracle 121 manual says there is one crucial difference between columns and cols: This view (ALL_TAB_COLUMNS) filters out system-generated hidden columns and invisible columns, which are user-generated hidden columns. The ALL_TAB_COLS view does not filter out hidden columns and invisible columns.

Pretty, huh? I did not know the detail. I accidentaly stumbled upon it, when I discovered some unwanted extra columns in ALL_TAB_COLS. Reported as a schema difference.