Re: [HACKERS] Oops, I seem to have changed UNION's behavior - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: [HACKERS] Oops, I seem to have changed UNION's behavior
Date
Msg-id 199905101826.OAA04574@candle.pha.pa.us
Whole thread Raw
In response to Re: [HACKERS] Oops, I seem to have changed UNION's behavior  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
> Thomas Lockhart <lockhart@alumni.caltech.edu> writes:
> >>>> Am I right in thinking that UNION (without ALL) is defined to do a
> >>>> DISTINCT on its result, so that duplicates are removed even if the
> >>>> duplicates both came from the same source table?  That's what 6.4.2
> >>>> does, but I do not know if it's strictly kosher according to the SQL
> >>>> spec.
> 
> > (Just in case this is still active)
> 
> > Yes, this is the right behavior according to SQL92...
> 
> OK, then 6.5 is still broken :-(.  I know a lot more about the planner
> than I did then, so I will see if I can fix it "right" --- that is,
> without taking out equal()'s ability to detect equality of Query nodes.
> 
> If that seems too hard/risky, I will just lobotomize equal() instead.
> 
> Thanks for the reminder, Bruce --- I had forgotten about this issue.

Hey, that's why I keep 500 messages in my PostgreSQL mailbox.

--  Bruce Momjian                        |  http://www.op.net/~candle maillist@candle.pha.pa.us            |  (610)
853-3000+  If your life is a hard drive,     |  830 Blythe Avenue +  Christ can be your backup.        |  Drexel Hill,
Pennsylvania19026
 


pgsql-hackers by date:

Previous
From: Bruce Momjian
Date:
Subject: Re: [HACKERS] Minor pg_dump buglet
Next
From: Bruce Momjian
Date:
Subject: Re: [HACKERS] inet data type regression test fails