Re: [HACKERS] Phantom row from aggregate in self-join in 6.5

At 11:39 AM 7/23/99 +1000, Philip Warner wrote:

>I've now checked Dec Rdb, SQL/Server, and MS-Access - and they return 0
rows. Add this to Informix, and one begins to wonder if there are any that
match the Postgres behaviour?

>Any idea where I can find a copy of the SQL92 standard on the net?

I'd like an answer to this, too :)

It may be that you've stumbled into an area the standard's either
left "implementation-dependent", "undefined", or simply forgotten
or unthought-of.  (can you tell I've been drafted into ANSI/ISO
standards efforts in the past for Pascal and Modula-2?)

Still, I must say that a row returning "0" in response to a 
count(*) isn't at all suprising, I guess it's a matter of 
whether or not the count(*) or the specific column being
extracted determines the behavior.

>>You'll find several past discussions of this point in the pgsql-hackers
>>archives, and they all seem to have ended inconclusively.

>I had a quick look at discussions involving informix, but could not find
anything. Can you give a little more information about the past
discussions, and specifically, what the reasons for preserving this
behaviour were?

First, I wouldn't trust Access to be much of an SQL standards judge.
If nothing else, MS's collaboration with Sybase (SQL/Server) might
perhaps color MS's view of what the standard sez. Not to mention 
the poaching of parser/semantic code, etc...

And doesn't DEC Rdb have some genealogical relationship to SQL/Server?
(I could be WAY off base here)



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