Re: Oracle Spatial Data Option

It might help if you gave us the SQL you wrote. Can we assume it was something like:

Can we assume it was effectively something like:

    select wards where ward is inside (

        select local government area where area = 'X'     )

and are ward non-overlapping, and does a set of wards cover a local government area, and are wards and local governments all stored in the same SDO_ set of tables ?

Also, how many wards, typically, in a local government area. (I am assuming that the 10,000 polygons is the whole map, rather than each polygon has 10,000 points)

If my assumptions are roughly correct the testing I have done in the past suggests that you should be able to return a few wards per second.

The query would be something like:

    select sdo_gid_target from (
    select distinct b.sdo_gid sdo_gid_target     from

        map_sdoindex A, map_sdoindex B
    where

        a.sdo_gid = {lga_id}
    and a.sdo_code = b.sdo_code
    )
    where

        sdo_geom.relate('map',{lga_id},'COVERS' sdo_gid_target) = 'TRUE'

Jonathan Lewis
Yet another Oracle-related web site: www.jlcomp.demon.co.uk

Neil Waller wrote in message <369ECBD7.C424E00A_at_denr.sa.gov.au>...
>Has anyone out there had experience with Oracle's Spatial Data
>Cartridge?
>
>We have it available in both Oracle 7.3.4 and Oracle 8.0.3 versions.
>
>My initial reaction is the initial spatial fetch is very quick but
>that the PL/SQL procedures to determine the spatial interactions
>can be very slow. I tried to find the Wards in a Local Government
>Area, and I'm talking 10000 cornered polygons here, and, in the time
>Oracle 8.0.3 SDO was doing its filtering I had written a bit of
>C++ code using the OCI and debugged and run it. My code could
>do in a few seconds what Oracle was taking hours to do.
>
>The situation isn't so bad when I try to find the towns (fairly
>small polygons) in a Local Government Area. This takes a couple
>of minutes rather than hours.
>
>The problem may be with my sql statements and their tuning but
>the OCI code was not tuned ...
>
>Any comments would be welcome.
>
>--
>Neil Waller (nwaller_at_denr.sa.gov.au)
>Department of Environment Heritage and Aboriginal Affairs
>Telephone: Oz: (08) 8204 9218; International: (618) 8204 9218
>Mail: GPO Box 1047, ADELAIDE 5001 Australia
Received on Fri Jan 15 1999 - 14:43:17 CST