From: | "Vadim B(dot) Mikheev" <vadim(at)sable(dot)krasnoyarsk(dot)su> |
---|---|
To: | Michael Hirohama <kamesan(at)ricochet(dot)net> |
Cc: | hackers(at)postgreSQL(dot)org |
Subject: | Re: Subselects open issue Nr. NEW |
Date: | 1998-02-17 03:31:16 |
Message-ID: | 34E90484.A150B16@sable.krasnoyarsk.su |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Michael Hirohama wrote:
>
> [...]
> >SQL> select * from a where (x,z) >= ANY (select y, l from b);
> >select * from a where (x,z) >= ANY (select y, l from b)
> > *
> >ERROR at line 1:
> >ORA-00920: invalid relational operator
> >
> >: only '=' and '<>' are allowed if there are more than one
> >expression on the left side of clause with subselect...
> >
> >Is this in standard or Oracle' preference ?
>
> This is a mathematical law.
>
> Vectors cannot be strictly ordered. "Partial orderings" are possible.
>
> Let A be (1, 2)
> Let B be (4, 7)
> Let C be (3, 5)
> Let D be (5, 10)
>
> A is smallest; D is largest; how do B and C relate?
I understand this. And this is how it works currently:
select * from tab where (A,B) >= ANY (select X, Y from tab2);
means: select tuples where A >= X _and_ B >= Y for some tuple from tab2.
^^^^^
'AND' is used for all Op-s except for '<>' when 'OR' is used.
Question is "should we drop this feature (?) or leave it as is ?"
Comments ?
Vadim
From | Date | Subject | |
---|---|---|---|
Next Message | The Hermit Hacker | 1998-02-17 03:42:37 | Re: [QUESTIONS] Trouble creating view\ |
Previous Message | Bruce Momjian | 1998-02-17 03:15:58 | Re: DB logging (was: Problem with the numbers I reported yesterday) |