Jim C. Nasby wrote:
On Tue, Nov 08, 2005 at 07:21:34PM -0500, Tom Lane wrote:
... the most straightforward thing to do is define an empty element
as meaning a NULL. But this might be objected to on a couple of grounds:
I just thought of another, potentially fatal objection: it's ambiguous
whether '{}'::text[] should be taken to mean an empty (zero-length)
array or an array containing a single NULL element.
For backwards compatibility it should mean an empty array, but then
there's no way to represent ARRAY(NULL) in data dumps, which won't
do either.
The only workaround that comes to mind is to allow explicit
specification of what's meant: '[1:1]{}' would be needed to represent
the one-null case. Ugly.
Instead of bending over backwards to try and support older cases, would
a compatability mode be possible? Seems that would solve a lot of
problems.
Last time I thought about this problem, that's what I concluded. I don't
think there is a reasonable and backward compatible solution.
I also think the best non-compatible solution is to require non-numeric
elements to be delimited (double quotes, configurable?), and use NULL
unadorned to represent NULL.
Joe
---------------------------(end of broadcast)---------------------------
TIP 1: if posting/reading through Usenet, please send an appropriate
subscribe-nomail command to [EMAIL PROTECTED] so that your
message can get through to the mailing list cleanly
