How to combine spatial and secondary index, when extracting?

Question

Hi spatiallers,
vers.: (32 bit) Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production on Sun/SunOS 5.8 (64 bit)
In our DataWarehouse the table topo_geodata stores all topographic data in Denmark. The table has a spatial index (QT) on its SDO_geometry column named utm_geo as well as a primary key on the column topo_geo_id and 4 secondary indexes on other columns.
The query to find all geomtries in a given munipalicy is as follows
select count(*) as antal_AnyInteract_topo_geodata
from topo_geodata k, topo_geodata tg
where SDO_RELATE(tg.utm_geo, k.utm_geo, 'mask=AnyInteract querytype= WINDOW') = 'TRUE'
and k.topo_geo_id = 961 -- geometry of a municipality
and it returns a count of 19445 in 4 minuttes. However our users are only interested in extracting certain object types, that is a very small subselection of the 19445 geometries. The subselection is typically based on some value or a range of values in the secondary indexed columns.
Question: How can I make the SELECT use a combination of the spatial index index and a secondary index?
Only when a pinpoint 1 particular value of the primary key do I get fast response. When pinpointing 1 value in a secondary index as in
select count(*) as antal1
from topo_geodata k, topo_geodata tg
where SDO_RELATE(tg.utm_geo, k.utm_geo, 'mask=AnyInteract querytype= WINDOW') = 'TRUE'
and k.topo_geo_id = 961 -- Gladsaxe
and tg.mtk_obj_id = 58476 -- has secondary index
the performance deteriorates back to 4 min., and the queryplan shows some weird bitmap conversion followed by a bitmap-and operation.
- Thanks in advance,
Jens Ole Jensen
Kort & MatrikelStyrelsen (WWW: http://www.kms.dk)
Danmark

Answer 1

Hi Jens,
I'm not sure I understand the question, or what it is that works fast.
In this case, the SDO_RELATE with the anyinteract mask has to be done first.
If this takes 4 minutes, then adding additional criteria to reduce the amount of
data returned from that subset will only add time.
The spatial portion of the query has to be done using the spatial index, which is
a monolithic index for the whole table, so all of the geometry data has to be searched,
and the anyinteract applied to all of this data.
After that set of rows comes back, then the additional predicate is applied.
I'm not sure what this means:
Only when a pinpoint 1 particular value of the primary key do I get fast response. You do have a few options to try to make things work faster:
If queries included additional predicates on mtk_obj_id, you might try
to use range partitioning.
If the predicates on mtk_obj_id is very selective, then you might want to select
values based on that column, then use sdo_geom.relate between that very
small subset and the query window.
Hope this helps, and all is well with you.
Dan