[mapguide-users] Query for Oracle SDO Data without using SDO_FILTER

[Traian Stanev]

When viewing maps/layers in MapGuide there will always be a spatial
query, regardless of the data source. The only way to change this
(currently) would be to edit the source code -- the relevant section is
in StylizationUtil::ExecuteFeatureQuery(). I agree it would be nice to
be able to set something in the layer that skips the spatial query -- it
would be nicer still if Oracle didn't need workarounds in order to,
well, work.


Traian
 

-----Original Message-----
From: Johann Nothbauer [mailto:nothbauer at rmdata.at] 
Sent: Friday, November 17, 2006 6:55 AM
To: OSGEO Mapguide Users
Subject: [mapguide-users] Query for Oracle SDO Data without using
SDO_FILTER

Is there any way to prevent Mapguide from using the SDO_FILTER()=='TRUE'

- Clause for Layers of Oracle Spatial Feature Sources?

I'm trying to produce an overview layer from an Oracle table containing
a lot of Line Features (> 2 million). The Features, that should be part
of the overview can be found with a very simple predicate (e.g.: "where
layername = 'GG'") and are very few (< 1000). My problem is, that
Mapguide always sends a combined query (simple predicate plus spatial
query with "extent all"). The Oracle explain plan shows, that internally
ALL Features are fetched into memory as a result of the spatial query
only to be filtered with the much "better" simple predicate.
I see this is a problem of the Oracle Cost Based Optimizer.

A nice workaround could be a "Don't use Spatial Filter" Checkbox in
Mapguide (as available in Oracle Mapviewer).

Would this be possible for the currrent Design?


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