Help tuning an Oracle query

[sb2c]

Hello,
I am somewhat new to Oracle, and could use some help tuning a query. I have a view (view_unused_fill) that joins two tables:

SELECT ...
FROM ratings r, unused_fill f
WHERE f.qh_key=r.qh_key AND
f.network=r.abbr_traffic AND
r.rpt_type='dma'

The tables have indexes on the columns used in the join.

Next what I need to do is get a list of min and max dates visible in this view, grouped by the contract_no. Here is that query:

select v.contract_no tvno, min(trunc(v.fill_dt,'dd')) mindate, max(trunc(v.fill_dt,'dd')) maxdate
from view_unused_fill v
group by v.contract_no
order by v.contract_no

The problem is that this query takes 2 minutes to run. It seems like it should be possible to make it run faster.

Here is an Explain Plan of the query. I don't know what this means, but shouldn't it be possible to prevent the full table access of UNUSED_FILL by using an index? There is an index but the optimizer does not seem to want to use it.

SELECT STATEMENT Optimizer=CHOOSE
..SORT (GROUP BY)
....NESTED LOOPS
......TABLE ACCESS (FULL) OF UNUSED_FILL
......TABLE ACCESS (BY INDEX ROWID) OF RATINGS
........INDEX (UNIQUE SCAN) OF RATINGS_QHK_ABBR_TRAFFIC (UNIQUE)


The RATINGS table contains about 1.7 million records.
The UNUSED_FILL table contains about 180 thousand.

Any help is appreciated.

Thanks,
sb2c.