Thanks for the idea, Ben. I did look at this briefly, but thought I'd
pursue the simpler approach first. Although auto-simplification would be
much nicer if possible, since it would be more general purpose and give a
nicer visual appearance.
I think I've seen or heard that the Oracle SDO_UTIL.SIMPLIFY function is
very slow, so that might be an issue. However, it might be possible to
build a database function to provide faster/simpler simplification (e.g.
decimation).
On Tue, Mar 10, 2015 at 11:14 AM, Benjamin Trigona-Harany <
bo...@boundlessgeo.com> wrote:
> Hi Martin,
>
> PostGIS stores now (as of GeoServer 2.5) support an option to
> automatically use ST_Simplify on geometries, which would probably do
> exactly what you want if the functionality could be extended to Oracle
> stores. However, I do see Andrea's comment on simplification in Oracle was
> "Now, this is PostGIS specific (no plain simplification in Oracle, only the
> topology preserving one is available, which is supposedly more expensive
> than not doing it, at least, it is in PostGIS)".
>
> On 10 March 2015 at 11:00, Martin Davis <mtncl...@gmail.com> wrote:
>
>> We're working on tuning a GeoServer implementation over an Oracle SDO
>> database. We think we are seeing that the network latency of queries is the
>> hotspot in the performance of GeoServer render requests.
>>
>> It seems that for some situations one way to reduce the data being pushed
>> over the wire is to reduce the data size in the database query. In
>> particular, for some datasets of polygons we're happy just to see points
>> representing the polygons. So we tried using a SQLView with a statement
>> like:
>>
>> select GEOMETRY, SDO_GEOM.SDO_CENTROID(GEOMETRY, 1) PT from CUT_BLOCK_SP
>>
>> and then used an SLD <Geometry> selector to render just the point.
>>
>> However, this doesn't work because we get the dreaded ORA-13226:
>> interface not supported without a spatial index error. This is because
>> GeoServer is actually emitting the query
>>
>> SELECT PT as PT FROM (select GEOMETRY, SDO_GEOM.SDO_CENTROID(GEOMETRY, 1)
>> PT from CUT_BLOCK_SP t) VTABLE WHERE SDO_FILTER(PT, ?, 'mask=anyinteract
>> querytype=WINDOW') = 'TRUE'
>>
>> and there is no index defined on the PT column.
>>
>> Now, this would work if GeoServer could emit the query:
>>
>> SELECT PT as PT FROM (select SDO_GEOM.SDO_CENTROID(GEOMETRY, 1) PT from
>> CUT_BLOCK_SP t) VTABLE WHERE SDO_FILTER(GEOMETRY, ?, 'mask=anyinteract
>> querytype=WINDOW') = 'TRUE'
>>
>> Is there any way to get this to happen?
>>
>> Or does anyone have other ideas about how to reduce query data size on
>> Oracle?
>>
>>
>> ------------------------------------------------------------------------------
>> Dive into the World of Parallel Programming The Go Parallel Website,
>> sponsored
>> by Intel and developed in partnership with Slashdot Media, is your hub
>> for all
>> things parallel software development, from weekly thought leadership
>> blogs to
>> news, videos, case studies, tutorials and more. Take a look and join the
>> conversation now. http://goparallel.sourceforge.net/
>> _______________________________________________
>> Geoserver-users mailing list
>> Geoserver-users@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/geoserver-users
>>
>>
>
>
> --
>
> Benjamin Trigona-Harany
>
> Global Support Lead | Boundless <http://boundlessgeo.com>
>
> bo...@boundlessgeo.com
>
> +1-250-984-4141
>
> @boundlessgeo <http://twitter.com/boundlessgeo/>
>
>
>
------------------------------------------------------------------------------
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the
conversation now. http://goparallel.sourceforge.net/
_______________________________________________
Geoserver-users mailing list
Geoserver-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/geoserver-users
