VERY SLOW UPDATES

This is my situation...
My table has about 1.6 million records.
I am trying to use the update command to insert new data.
However, it is extremely slow--about 2 to 4 seconds per update.
You can see my problem is I am trying to update 40,000 records.
Any insight or suggestion would be appreciated.
-Ken

PS I am currently wrapping my updates in a transaction block and indexes
have been dropped.

______________________________________________________

Kenneth P. Grembowicz
Oceanographic Databases Division, Code N51
Naval Oceanographic Office
1002 Balch Blvd.
Stennis Space Center, MS 39522-5001
Tel: (228) 688-5675
Fax: (228) 688-5778
e-mail: grembowiczk(at)navo(dot)navy(dot)mil