Database Software

Hello,
I had a table with polygon features, and I created centerpoints for them. I noticed that I have mulitple centrepoint records and I only want one for each geometry. In some cases I have 22 points for 1 unit, when I should only have 1.
I have a field for point geometry.
ex. where id=1, GEOMETRY= SDO_GEOMETRY(2001,NULL,NULL,SDO_ELEM_INFO_ARRAY(1,1,1,3,1,0), SDO_ORDINATE_ARRAY(-122.88808, 49.2634761, .999999,531,-.0009687))

NOTE: I created the centrepoints using Geomedia, as there were too many issues using oracle and my original shapefile had no unique id.

What I would like to do is create a table that has the rowid and x,y of points so that I have only distinct geometries. My rough statement is:
create table tmp_1 as select x,y,min(rowid) "RT" from ADDRESS group by x,y;

create table tmp_2 as select from ADDRESS where row_id in (select RT from tmp_1);*

Any ideas on how I can fix this? I have tried to do 'CREATE TABLE TMP_1 AS SELECT GEOMETRY, MIN(ROWID) "RT" FROM ADDRESS GROUP BY GEOMETRY;' but i got ORA-22901: cannot compare nested table or VARRY or LOB attributes of an object type.

Thank you!