Prior to this change if someone provided a column that had mixed case but their engine was case sensitive we wouldn't see this as a duplicate column name to replace the existing one and therefore create a duplicate column. This normalizes the value so the check should be correct now.
Prior to this change if someone provided a column that had mixed case but their engine was case sensitive we wouldn't see this as a duplicate column name to replace the existing one and therefore create a duplicate column. This normalizes the value so the check should be correct now.