[fdo-dev] Create nonspatial index in SDF via FDO?

Jason Birch Jason.Birch at nanaimo.ca
Tue Sep 12 18:22:56 EDT 2006


Thanks for the responses Traian, Badreddine,

This is for an web app that I didn't write, so I didn't have direct
access to performance metrics.  I was hoping to be able to set an index
to see if it got any better.

I've since set up a test bed for this and it appears that even without
an index the response is not too bad (there's a huge difference between
a straight query vs. the web app).

That said, if it's simple to add an attribute index to the SDF format
that would be a good thing, as I often query by attributes other than
the IDENTITY column.

Jason


-----Original Message-----
From: Traian Stanev [mailto:traian.stanev at autodesk.com] 
Sent: Tuesday, September 12, 2006 13:06
To: dev at fdo.osgeo.org
Subject: RE: [fdo-dev] Create nonspatial index in SDF via FDO?


Hi Jason,

I don't think it's possible to have SDF index on anything other than
geometry and key.
I am not surprised that performance is bad when filtering on other
attributes, since it would be doing a linear search through the features
and evaluating the filter for each feature.

If you tell me more details about your use case, may be I can think of a
workaround.

Traian

-----Original Message-----
From: Jason Birch [mailto:Jason.Birch at nanaimo.ca]
Sent: Tuesday, September 12, 2006 3:55 PM
To: dev at fdo.osgeo.org
Subject: RE: [fdo-dev] Create nonspatial index in SDF via FDO?

Is this not an appropriate place to ask this question?  Is there
somewhere better?

Thanks,
Jason 

-----Original Message-----
From: Jason Birch [mailto:Jason.Birch at nanaimo.ca]
Sent: Monday, September 11, 2006 19:18
To: dev at fdo.osgeo.org
Subject: [fdo-dev] Create nonspatial index in SDF via FDO?

Hi all,
 
Is it possible to create a non-spatial (attribute) index in the SDF
format using FDO?  I'm seeing really poor performance on queries with
attribute filters applied on a fairly small (14000 row) table and I'd
like to try applying an index to see if it makes a difference.
 
I know that SQLite supports attribute indexes
http://www.sqlite.org/lang_createindex.html
but can't find a method in FDO to create them, and the SQLite tools
don't seem to like opening up SDF3 files directly.  Any ideas?
 
Thanks,
Jason

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