[Firebird-docs] langref ORDER BY incorrect caution

[Mark R. <ma...@la...>]

While going over the language reference to do some manual fixes, I came 
across the following caution (see 
https://firebirdsql.org/file/documentation/reference_manuals/fblangref25-en/html/fblangref25-dml-select.html#fblangref25-dml-select-orderby-unions

"""
Expressions whose calculation results are non-negative integers will be 
interpreted as column position numbers and will cause an exception if 
they fall outside the range from 1 to the number of columns.

Example:

     SELECT
       X, Y, NOTE
     FROM PAIRS
     ORDER BY X+Y DESC


* The number returned by a function or a procedure is unpredictable, 
regardless of whether the sort order is defined by the expression itself 
or by the column number
* Only non-negative integers are interpreted as column numbers
* An integer obtained by one-time evaluation of an expression or by 
parameter substitution is saved as a constant, because this value 
applies to all rows.
"""

I just tested this in Firebird 2.5 and 1.5, and this is not actually the 
case (and I would be surprised if it ever has been the case). The value 
of an expression itself is used to sort. As far as I'm aware only 
literal or parenthesized literal values can be used to identify column 
positions.

Any objections if I just remove this caution in the new version?

Mark
-- 
Mark Rotteveel