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

[Johann Nothbauer]

Hi Andy!

I'm using Mapguide Open Source 1.0.2.
I could try to use Mapguide Enterprise, for we are a Autodesk Partner.

I'm only wondering how Mapguide would automatically decide when not to 
use the Spatial Filter?

cheers,
Johann



Andy Morsell wrote (Date: Fri, 17 Nov 2006 08:54:22 -0800):

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?