AW: [HACKERS] Re: Subselects open issue Nr. NEW
От | Zeugswetter Andreas SARZ |
---|---|
Тема | AW: [HACKERS] Re: Subselects open issue Nr. NEW |
Дата | |
Msg-id | 219F68D65015D011A8E000006F8590C6010A51DD@sdexcsrv1.sd.spardat.at обсуждение исходный текст |
Список | pgsql-hackers |
I allready took my statement back, about an hour after I said this. But yes, I agree that the left-right approach would be intuitive (same as compound index). In mathematics it is called lexical order, I only thought this would be hard to implement. Also there are a lot of operators (all negated Op's that) will want an _OR_ e.g. !=~, not only <> So all not very easy, I'll try to think some more about it. Andreas > ---------- > Von: Bruce Momjian[SMTP:maillist@candle.pha.pa.us] > Gesendet: Dienstag, 17. Februar 1998 17:15 > An: Zeugswetter Andreas SARZ > Cc: pgsql-hackers@hub.org > Betreff: Re: [HACKERS] Re: Subselects open issue Nr. NEW > > > > > Gosh, please leave it in it is superb, great, fantastic ... > > If somebody defines a different behavior as standard in the future, > > we will need to tell him that he has a gordian knot in his brains :-) > > > > Andreas > > > > > 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 ?" > > > > > > > > I think my recent posting answers this. You have to comare from > left-to-right until you find an answer. > > -- > Bruce Momjian > maillist@candle.pha.pa.us > >
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