Kjell Rilbe wrote:

>
> The server *knows* N.

If your N means "bytes actually used", then you're wrong. CHARs are not
padded when transmitted. They're stored padded and the padding character
is a proper part of the string (accordingly to the SQL standard, BTW).
The engine doesn't care how many non-spaces are there, so it cannot help
you with knowing N. The same goes for "characters actually used", as the
only fact it knows is that CHAR_LENGTH(CHAR(X)) == X, again regardless
of how many non-spaces are there.


Dmitry