I came across this statement in the official Oracle documentation:
In Microsoft SQL Server, only columns with variable-length data types can store NULL values. When you create a column that allows NULLs with a fixed-length data type, the column is automatically converted to a system variable-length data type...
I have never read about this in the SQL Server docs nor have I experienced such a thing. On the contrary: in SQL Server, fixed-length data types (such as int and float, but also char) are heavily used and stored very efficiently even when NULLable.
Is there any rationale behind this Oracle statement?!