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

[Andy Morsell]

Are you using MapGuide Enterprise with Service Pack 1?  SP1 fixed quite a
few of the Oracle Spatial performance issues. 


Andy 

-----Original Message-----
From: Johann Nothbauer [mailto:nothbauer at rmdata.at] 
Sent: Friday, November 17, 2006 3:55 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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