Re: [QUESTIONS] Attn PG gurus / coders : New approach for ORDER BY ? (was: Re: Show stopper ?)

On Fri, 23 Jan 1998, Jan Vicherek wrote:
[big chop]

>    This looks like a sad suggestion to me. I'll kick and scream just that
> I wouldn't have to go with Velocis RAIMA's lower-level C interface. (I'm
> just staring into its manual to figure out the sequence of C calls I would
> have to make to accomplish this.)

If it is still the same as when it was called DBVista... then

    d_keyfind(xx,x,x)
    while(db_status == S_OK)
       {
       d_recread(x,x,x,x);
       d_keynext(ssss);
       }
(No error checking in that code...<g>)

------------ end Raima note ------------------------------------

BUT - the functionality you want could be a special case of the Postgres
backend and would benefit a very important real world scenario
(scrolling inquiries)

IF - declare cursor
  and select 'whole table'
  and 'order by a field which is a key'

Treat as special - dont handle ANY data until the FETCH statement.
  IE. Defer the IO until the fetch happens -  then access the row(s)
      via the index

This would give an enormous boost in effective performance with the common
application task of a scrolling inquiry against a large table.
Implementing it would be transparent to current application code and would
offer a competitive edge over other products without it.

Normally I'm not one to support 'special case' coding tricks, but the
public impact on visible performance probably justifies looking into this
a bit further.
I suspect the query processor can identify the situation. It would need to
remember that it was special and leave enough control info to allow the
'fetch' processing to respond to that special case.

Comments from the guru's who are up to their necks in the code ?

Regards
Ron O'Hara

>
>
>    Thanx to all,
>
>         Jan
>
>  -- Gospel of Jesus is the saving power of God for all who believe --
> Jan Vicherek ## To some, nothing is impossible. ##  www.ied.com/~honza
>     >>>    Free Software Union President  ...  www.fslu.org    <<<
> Interactive Electronic Design Inc.    -#-    PGP: finger honza@ied.com
>
>