R: [postgis-users] ST_<function> vs <function>
P.Rizzi Ag.Mobilità Ambiente
paolo.rizzi at ama-mi.it
Tue Sep 11 02:57:07 PDT 2007
> >>> Most if not all of the ST relation functions have
> automatic index use
> >>> enabled in them.
So, using the new ST_ functions, one won't have to use && anymore, that's great!!!
But what about the old non-ST_ functions, are they mapped to the new ones or not???
That is, if I use the old non-ST_ functions will I have to use an explicit && or not???
And the other way around, if I use the new ST_ functions _and_ an explicit &&,
will it be transparently optimized or will I incur a performance penalty???
Just to know how to write SQL that works well with both old and new PostGIS.
Bye
Paolo Rizzi
> -----Messaggio originale-----
> Da: postgis-users-bounces at postgis.refractions.net
> [mailto:postgis-users-bounces at postgis.refractions.net]Per conto di
> Barend Köbben
> Inviato: martedì 11 settembre 2007 8.26
> A: PostGIS Users Discussion
> Oggetto: Re: [postgis-users] ST_<function> vs <function>
>
>
> The SQL-MM specification has ST_ as a prefix to all spatial
> funcionality
> (types, functions), and the newer PostGIS functions will
> follow that spec...
>
>
> On 11-09-2007 02:42, "Stephen Woodbridge"
> <woodbri at swoodbridge.com> wrote:
>
> > This is all I could find:
> >
> > Log:
> > Added versions of functions with standard ST (Spatial Type)
> prefixes to
> > any functions that were lacking them. Updated the
> regression tests to
> > include the new functions.
> >
> >
> > Richard Greenwood wrote:
> >> I'm embarrassed to ask, but what does "ST" stand for?
> >>
> >> Rich
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >> On 9/10/07, Obe, Regina <robe.dnd at cityofboston.gov> wrote:
> >>>
> >>>
> >>> Steve,
> >>>
> >>> Just to add to what Mark said. There is a little bit
> more going on than
> >>> simply a renaming.
> >>>
> >>> Most if not all of the ST relation functions have
> automatic index use
> >>> enabled in them.
> >>>
> >>> For example
> >>>
> >>> the old within is really closer to the hidden _ST_Within
> and the new
> >>> ST_Within function is equivalent to writing the old
> >>>
> >>> geom1 && geom2 AND Within(geom1, geom2)
> >>>
> >>> Same goes for ST_Contains, ST_Overlap etc.
> >>>
> >>> Hope that helps,
> >>> Regina
> >>>
> >>> ________________________________
> >>> From: postgis-users-bounces at postgis.refractions.net on
> >>> behalf of Mark Cave-Ayland
> >>> Sent: Sun 9/9/2007 4:30 PM
> >>> To: PostGIS Users Discussion
> >>> Subject: Re: [postgis-users] ST_<function> vs <function>
> >>>
> >>>
> >>>
> >>>
> >>> On Sun, 2007-09-09 at 16:03 -0400, Stephen Woodbridge wrote:
> >>>> Hi all,
> >>>>
> >>>> I seem to have missed reading some vital post or something.
> >>>>
> >>>> What is the difference between ST_<function>() and <function>()?
> >>>> Is this just a renaming for namespace issues?
> >>>> Are the <function>() names deprecated?
> >>>> Are there other benefits to this renaming?
> >>>>
> >>>> Please explain or point me to the relevant docs.
> >>>>
> >>>> Thanks,
> >>>> -Steve
> >>>
> >>> Hi Stephen,
> >>>
> >>> I don't remember there being much discussion about this, but the
> >>> relevant commit can be found here:
> >>>
http://postgis.refractions.net/pipermail/postgis-commits/2007-June/000074.ht
>>> ml.
>>> In short, the old function names are deprecated, and new applications should
>>> start to use the ST_ prefix functions instead.
>>>
>>>
>>> ATB,
>>>
>>> Mark.
>>>
>>> --
>>> ILande - Open Source Consultancy
>>> http://www.ilande.co.uk
>>>
>>>
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>>
>>
>
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