On Tue, 2007-08-07 at 17:46 -0500, Decibel! wrote:
> On Sun, Aug 05, 2007 at 08:18:08PM +0530, Merlin Moncure wrote:
> > On 8/3/07, Guy Fraser <guy(at)incentre(dot)net> wrote:
> > > On Wed, 2007-08-01 at 07:14 +0530, Merlin Moncure wrote:
> > > > On 8/1/07, Decibel! <decibel(at)decibel(dot)org> wrote:
> > > > > David Fetter and I just came up with these, perhaps others will find
> > > > > them useful:
> > > > >
> > > > > CREATE OR REPLACE FUNCTION array_to_set(anyarray, int) RETURNS SETOF anyelement LANGUAGE SQL AS $$
> > > > > SELECT $1[i] from generate_series(array_lower($1, $2), array_upper($1, $2)) i
> > > > > $$;
> > > > > CREATE OR REPLACE FUNCTION array_to_set(anyarray) RETURNS SETOF anyelement LANGUAGE SQL AS $$
> > > > > SELECT array_to_set($1, 1)
> > > > > $$;
> > > >
> > > > very nice, although IMO there is a strong justification for these
> > > > functions to be in core and written in C for efficiency (along with
> > > > array_accum, which I have hand burn from copying and pasting out of
> > > > the documentation).
> > > >
> > > > merlin
> > > >
> > > Excellent timing guys. :^)
> > >
> > > I was trying to build a function to list the items of an array, but
> > > ran into problems and was going to post what I had been working on.
> > >
> > > Your functions work great.
> > >
> > > In case you don't have the function to generate an array from a set
> > > here is one I have been using :
> > >
> > >
> > > CREATE AGGREGATE array_accum (
> > > BASETYPE = anyelement,
> > > SFUNC = array_append,
> > > STYPE = anyarray,
> > > INITCOND = '{}'
> > > );
> >
> > I think that's what just about everyone uses. Unfortunately the
> > reverse of the function (array_to_set above) AFAIK does not map
> > directly to the C array API.
>
> Oh, cool, hadn't thought about using an aggregate to do this. That's
> probably faster than what I came up with.
You are welcome. I am glad someone appreciated my gesture.