Shape retrieval; finding all polygons in a huge grid;dynamic grid

Question

Hi.
1) Is it possible to find (fast) all shapes (eg. polygons) in huge 2D grid? and if yes how can I do it? or do I have to cluster (or sort) my shapes first to make the search fast?
2)Is it possible to define a dynamic Grid
not like
SDO_DIM_ARRAY( -- 20X20 grid
SDO_DIM_ELEMENT('X', 0, 20, 0.005),
SDO_DIM_ELEMENT('Y', 0, 20, 0.005)
but sthing like
SDO_DIM_ARRAY( SDO_DIM_ELEMENT('X', 0, infinit, 0.05), SDO_DIM_ELEMENT('Y', 0, infinit, 0.05)
thx

Answer 1

no i am searching for something I haven't found neither in Oracle Spatial nor in Oracle spatial topology and network... documentation.
Here is what I have:
CREATE TABLE graphs ( id NUMBER PRIMARY KEY, name VARCHAR2(32), shape SDO_GEOMETRY, geom_id NUMBER);
INSERT INTO Graphs VALUES( 1, 'OBJECT 1', SDO_GEOMETRY(
2006, -- Multline string, 2 dimensions (X,Y),
NULL, NULL,
SDO_ELEM_INFO_ARRAY(1,1,8), SDO_ORDINATE_ARRAY(280,275, 208,168, 208,381, 280,275, 459,276, 90,168, 90,381)), 14);
INSERT INTO Graphs VALUES(2, 'OBJECT 2',SDO_GEOMETRY(2006,NULL,NULL,SDO_ELEM_INFO_ARRAY(1,1,6), SDO_ORDINATE_ARRAY(15,17,10,16, 20,38, 28,27, 459,276, 90,168)), 15);
INSERT INTO user_sdo_geom_metadata(TABLE_NAME,COLUMN_NAME,DIMINFO,SRID)VALUES('Graphs','shape',SDO_DIM_ARRAY(SDO_DIM_ELEMENT('X', 0, 600, 0.05),SDO_DIM_ELEMENT('Y', 0, 600,0.05)),NULL);
CREATE INDEX Graphs_spatial_idx ON Graphs(shape) INDEXTYPE IS MDSYS.SPATIAL_INDEX;
If I would like to know if another Multiline- object (geometry2) with the coordinates 280,275, 208,168, 208,381 is in "object 1" anywhere in my table I can use something like SDO_COVERS(geometry1, geometry2);
AND NOW here is my problem. Supposed I don 't have the coordinates of geometry2 but an equal Multiline (equal in considering the shape for example like 180,175, 108,68, 108,281). Is there a way to search over all my geometrys in my table if geometry2 COVERS IN ANY WAY (any direction) the geometry in the table. I could code the problem in java but I would like to know if Oracle Spatial or Topology network has functions that support subgraph search.