Originally posted by ashley75
There were about 600,000 rows in the table,
and 51 rows where grid_lvl=2
It's doing a full tablespace even I had the index for grid_lvl in there.
Still without anwer followig questions:

1) "only 51 rows where grid_lvl=2" but what about # of DISTINCT KEYS in this index
2) How many (or %) null values in this field.

Try to execute:

select distinct(grid_lvl) from spatial.grid_master;
select count(grid_lvl)/count(*), count(*) from spatial.grid_master;

Probably this information will be very helpful for u and u can deside :
Why oracle didn't use index?