RE: [HACKERS] 6.5 beta and ORDER BY patch

> -----Original Message-----
> From: Bruce Momjian [mailto:maillist@candle.pha.pa.us]
> Sent: Sunday, May 09, 1999 8:56 PM
> To: Hiroshi Inoue
> Cc: Hannu Krosing; David Hartwig; Jan Wieck; pgsql-hackers
> Subject: Re: [HACKERS] 6.5 beta and ORDER BY patch
> 
> 
> It is my assumption this has been applied to 6.5 beta, right?
>
It has been applied with subject  [Index backward scan patch].
However it doesn't include a change to omit sorting in all descending 
ORDER BY cases.  

Thanks.

Hiroshi Inoue
Inoue@tpf.co.jp

> [Charset iso-8859-1 unsupported, filtering to ASCII...]
> > Hello all,
> > 
> > > -----Original Message-----
> > > From: owner-pgsql-hackers@postgreSQL.org
> > > [mailto:owner-pgsql-hackers@postgreSQL.org]On Behalf Of Hannu Krosing
> > > Sent: Thursday, February 04, 1999 3:43 AM
> > > To: Jan Wieck
> > > Cc: hackers@postgreSQL.org
> > > Subject: Re: [HACKERS] 6.5 beta and ORDER BY patch
> > >
> > 
> > [snip]
> >  
> > > 
> > > After that the reverse index scans, so that the index that are 
> > > backwards can also be used for sorting.
> > > BTW, can this be easily implemented/effective in PostgreSQL or are
> > > our btree indexes optimised for forward scans ?
> > >
> > 
> > PostgreSQL seems to have the ability to scan Index backward 
> > because we can execute "fetch backward" command. 
> > IMHO _bt_first() fucntion used to find first item in a scan should 
> > be changed to work well in case of backward positioning.
> > 
> > I think this change also gives the partial solution for the problem 
> > [ [HACKERS] Cursor Movement - Past the End ] reported by 
> > David Hartwig. 
> > 
> > I have a sample code for this change.
> > I can send it if someone want to check or test it.
> >  
> > Thanks.
> > 
> > Hiroshi Inoue
> > Inoue@tpf.co.jp
> > 
> > 
> 
> 
> -- 
>   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, Pennsylvania 19026
>