[postgis-users] RE: PostgreSQL/PostGIS and ArcGIS Server 9.3

[Ragi Y. Burhum]

I forgot to change the subject. My sincere apologies.

On Fri, May 23, 2008 at 3:26 PM, Ragi Y. Burhum <ragi at burhum.com> wrote:

>  I guess this is a good time for me to give my two cents.
>
> A few disclaimers and background : Until last year, I worked at ESRI. I
> contributed with some of bug fixes for the PostgreSQL/PostGIS support in the
> ArcObjects side of things. I have also been using PostgreSQL and PostGIS for
> *many* years now. I follow many blogs (including yours Paul) but don't
> usually respond for obvious reasons. I have been known to circulate some
> various postings of criticism among places I have worked (or am working) at
> like ESRI, MS, etc. Chances are, you are running some of my code in some
> O.S. application and you don't even know it thanks to the beauty of Internet
> anonymity :)
>
> That being said, here are a few answers to some of your questions:
>
>
>>
>> Date: Sat, 24 May 2008 02:05:14 +0800
>> From: Tim Bowden <tim.bowden at westnet.com.au>
>> Subject: Re: [postgis-users] PostgreSQL/PostGIS and ArcGIS Server 9.3
>> To: PostGIS Users Discussion <postgis-users at postgis.refractions.net>
>> Message-ID: <1211565914.5940.108.camel at edoras>
>> Content-Type: text/plain
>>
>> On Fri, 2008-05-23 at 10:15 -0700, Paul Ramsey wrote:
>> >> SDE allows you to use ArcMap as a client. That's the main value
>> proposition.
>> >>
>
>
> That's not entirely accurate. ArcSDE allows you to use the ArcGIS
> ArcObjects GeoDatabase Layer. This includes the ArcGIS Server, ArcMap,
> ArcCatalog, ArcEngine Apps, and everything that is supported by that layer:
> Raster, TIN, Topology, Versioning, Geometric Networks, Network Datasets,
> Representations Layers, Annotations, Dimension Feature Classes, Cadastral
> Fabrics to name a few.
>
>
> >> Secondarily, there's some stuff, most particularly versioning, that
> >> they implement by managing extra metadata in side tables.  This is
> >> where your concern regarding 3rd party edits to PostGIS data come to
> >> reality. If you start mucking with the data, particularly versioned
> >> data, outside the SDE environment, you can put it into an inconsistent
> >> state.
> Mostly everything is implemented by managing extra metadata tables.
> However, that doesn't mean that there is not a mechanism for you to work
> with those tables directly. As far as versioning goes, multiversion views
> allow you to modify the simple features in versioned tables through the SQL
> prompt directly and allowing the data to remain consistent.
>
>
> > Ok, versioning is potentially quite valuable, depending on how well it's
> > implemented.  I imagine the editing problem exists for both inserts and
> > updates.  Pity, as it would be nice to at least put new geometries
> > directly into PostGIS without upsetting SDE.
>
> You can do this with Simple Features. ArcSDE allows you to 'configure' how
> you want to store your geometry in the underlying database. Do you want to
> use the ESRI PostgreSQL type? Do you want to use the PostGIS type? etc. Your
> choice will have different advantages/disadvantages.
>
> >> Also, you need some knowledge of the SDE scheme in order to properly
> >> *read* the information out of a versioned system with a 3rd party
> >> tool, since the data in the tables will include shapes from multiple
> >> versions.
> >>
> >So if I've understood correctly, if you aren't interested in versions,
> >but only the latest and greatest geometries, you should be fine doing a
> >direct read of the PostGIS geometries.
> See above for multiversioned views in regard to versioning. As long as you
> are not using ESRI Complex Feature Types (Topology, Geometric Networks, etc)
> you are correct.
>
> >> In general, if you restrict yourself ot reading with 3rd party tools
> >> and writing with ESRI tools, or non-ESRI tools working through the SDE
> >> API, you should be safe.
> >>
>
> True.
>
> >> Yes, using SDE effectively castrates the spatial database. It still
> >> walks and talks, but it's a shell of the man it was before.
> >>
>
> This is where we disagree. Although hammers are good, sometimes you need a
> screwdriver. The right tool for the right job.
>
> >Ah, but a much cheaper shell than previously available to SDE users
> >(with at least 87%(?) of the performance as I vaguely recall from some
> >semi-relevant benchmark study)!
> Oh... so relative.
> Anyway guys, thanks for the great work in PostGIS. Some of us use it and
> even evangelize extensively on certain situations... despite getting stabbed
> with hate comments every once in awhile.
>
> Can't we all just get along? :-)
>
> - Ragi Yaser Burhum
>
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