I posted this message to comp.databases.theory on 2003-08-01. The
original question happened to be about empty strings and nulls in
Oracle, but that is immaterial. In reposting now, I had to remove the
blanks after the '>' at the beginnings of the lines to avoid wrapping
in the editor I'm using - so the comment about "-\n> " would now omit
the blank.

=== Posted 2003-08-01 ===
andrewst wrote:
> Originally posted by Steve Kass
>> Theory and the ANSI/ISO standards, as far as I know, both
>> make a clear distinction between the known value '' and the
>> value NULL, which often makes best sense to think of as meaning
>> UNKNOWN.
>>
>> If you want to know why the designers of Oracle made this choice,
>> you might post the question in an Oracle newsgroup.
>
>
> This was already discussed in the Oracle group a while ago. We fell
> into 2 camps: those who understand the difference between '' and
> NULL and wished Oracle would too, and those who think whatever
> Oracle provides is The Truth, and that such distinction is
> therefore meaningless!
>
> This link should get you there:
>
>http://groups.google.co.uk/groups?hl...dm=3EEB5719.5-
>96F0280%40exxesolutions.com&rnum=1&prev=/groups%3Fq%3Dtony%2Bansi%2Bzer-
>o-length%2Bstring%2Bgroup:comp.databases.oracle.*%2B group:comp.database-
>s.oracle.*%26hl%3Den%26lr%3D%26ie%3DUTF-8%26group%3Dcomp.databases.orac-
>le.*%26selm%3D3EEB5719.596F0280%2540exxesolutions .com%26rnum%3D1

That URL got wrapped horribly, of course.

However, I've found by dint of experimentation on previous occasions
that you only need to specify the 'threadm' or 'selm' parts of the URL
data - which is usually short enough to fit on one line:

http://groups.google.co.uk/groups?th...olutions.c om

http://groups.google.co.uk/groups?se...esolutions.com

The reference is the message ID of a message in the thread.

In the example above, I had to remove "-\n> " from the threadm entry,
and I mapped "%3d" to "=" and replaced the "%25" in "%2540" with just
"%". But if you've just cut and pasted the URL from a Google search,
you should not have to mess with the mappings as much - just delete
the extraneous material.

I haven't tried with cross-posted messages and the like, so there's a
chance that other parts help choosing threads in the correct group(s),
but the shorter URL is generally beneficial.

=== End of Posting ===

After I posted this, Matt <matt@dds.tv> added a comment:
Or this, http://tinyurl.com/ivzj
Very useful for posting long URL's

--
Jonathan Leffler #include <disclaimer.h>
Email: jleffler@earthlink.net, jleffler@us.ibm.com
Guardian of DBD::Informix v2003.04 -- http://dbi.perl.org/