Re: Proposal: associative arrays for plpgsql (concept)

On Wed, 29 Jun 2005, Douglas McNaught wrote:

> David Fetter <david(at)fetter(dot)org> writes:
>
> > I'm all in favor of having associative arrays as a 1st-class data type
> > in PostgreSQL. How much harder would it be to make these generally
> > available vs. tied to one particular language?
>
> We already have them--they're called "tables with primary keys". :)
>
> What's the use-case for these things? Just imitating Oracle?
>
> -Doug
>

no

for example

DECLARE _d varchar[] INDEX BY VARCHAR = {'cmd1' => '723:t:f:1', 'cmd2'=>..
BEGIN
FOR r IN SELECT * FROM data LOOP
check_params(_r, _d[_r.cmd])
END LOOP;

or without assoc. arrays

DECLARE _d varchar;
BEGIN
FOR r IN SELECT * FROM data LOOP
SELECT INTO par _d WHERE cmd = _r.cmd;
check_params(_r, _d)
END LOOP;

I can't to speak about speed without tests but I can expect so hash array
can be much faster. This sample is easy, but I can have procedure witch
operate over big arrays of numbers(prices) and I need save somewhere this
arrays if I don't wont to read them again and again. And if I have in
data identification by key, I everytime have to find key, and translate it
into number

Regards
Pavel Stehule