Re: sort array optimisation in pl/perl

Hi,

thanks for this help.

The method functions great but the profit of time is good just if I have a
lot of elements to deplace.

COFRAMI
Nicolas Giroire
on behalf of AIRBUS France
for In Flight & Ground Information Services - Development
Phone : +33 (0)5 67 19 98 74
Mailto:nicolas(dot)giroire(at)airbus(dot)com

-----Message d'origine-----
De : pgsql-general-owner(at)postgresql(dot)org
[mailto:pgsql-general-owner(at)postgresql(dot)org]De la part de Ragnar Hafstað
Envoyé : jeudi 24 mars 2005 21:53
À : GIROIRE Nicolas (COFRAMI)
Cc : 'pgsql-general(at)postgresql(dot)org'
Objet : Re: [GENERAL] sort array optimisation in pl/perl

On Thu, 2005-03-24 at 15:49 +0100, GIROIRE Nicolas (COFRAMI) wrote:

> I create an array which is result of query on postgresql database and
> then I want to sort rows in a particular way (impossible by query on
> database).

can you give us more details on this particular sort order?

> My solution consists to put a rows (indice m+1) in a temporary other
> and then move all element before indice n to m in rows with indice n+1
> to m+1 and last i put my temporary variable to indice n.
> I want to know if somebody know a better solution.
>
> I think of 2 solutions but i don't success to apply :
> - the first is to use list in which I could deplace references as a
> chained list
> - the second will be to deplace tab[n..m] to tab[n+1..m+1] in one
> instruction as ada language

it all depends on the expected sizes of your arrays, but perl has
some nice array operations, such as slices and splice()

these come to mind:

$x=$arr[$m+1];@arr[$n+1(dot)(dot)$m+1]=(at)arr[$n(dot)(dot)$m];$arr[$n]=$x;

or:

@arr[$n..$m+1]=($arr[$m+1],@arr[$n..$m]);

gnari

---------------------------(end of broadcast)---------------------------
TIP 5: Have you checked our extensive FAQ?

http://www.postgresql.org/docs/faq

This mail has originated outside your organization,
either from an external partner or the Global Internet.
Keep this in mind if you answer this message.