Re: [udig-users] Oracle: sdo_aggr_mbr vs user_sdo_geom_metadata

["Simon Greener" <simon@xxxxxxxxxxxxxxxxxxxx>]

Greetings,
(Jodie, I'm on holidays in NZ. Back Sept 3rd.)
I learned  when programming GeoRaptor that you
can access the root mbr of the Oracle RTree
in user_sdo_index_metadata (column sdo_root_mbr).
This is an sdo_geometry object. However,
when it contains the mbr of a gedetix layer,
we haven't worked out what the
sdoordinates mean, as yet.
But is is blindingly faat: better tahn aggr union.
Code is in metedatatool.java in sourceforge repository.
best i can do.
simon
On Thu, 19 Aug 2010 14:23:32 +1000, Jody Garnett <jody.garnett@xxxxxxxxx> wrote:

> Hi Brandon.
>
> We had the previous version of our oracle support use the geom
> metadadata table; and I after treading the oracle manuals I though
> this was the correct approach to determine bounds.
>
> I got lots of negative feedback; apparently this table is not often
> filled in with the correct information and cannot be trusted.  With
> that in mind, when geotools created their "jdbc-ng" rewrite for oracle
> support they did not even considering taking the geom metadata table
> code used previous.
>
> If you like we can make the feature request for GeoTools and see what they say.
>
> With respect to SELECT SDO_AGGR_MBR ... I had thought that we avoided
> doing this for uDig 1.2.0 - instead assuming a default max extent
> based on the coordinate reference system.
>
> When Maurcio returns from vacation we can ask him, he performed the
> oracle testing for 1.2.0.
>
>
> Jody
>
> On Thu, Aug 19, 2010 at 4:37 AM, Bergenroth, Brandon
> <bbergenroth@xxxxxxx> wrote:
> > I have yet to see uDig (including 1.2.0) use user_sdo_geom_metadata,
> > instead, it seems to always insist on running
> >
> > SELECT SDO_AGGR_MBR(GEOMETRY) FROM BIG_SPATIAL_TABLE
> >
> > for every table in the schema.
> >
> > Will uDig ever use user_sdo_geom_metadata?  Running a full table scan on
> > every spatial table makes it pretty much useless for anything but a
> > trivial amount of data.
> >
> > Thanks,
> > Brandon
> >
> >
> >
> > _______________________________________________
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> > udig-users@xxxxxxxxxxxxxxxxxxxxx
> > http://lists.refractions.net/mailman/listinfo/udig-users
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--
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