Hello All

I have following table named TSH:

ID INTEGER
SITE VARCHAR(50)
WORK_DATE DATE

each day there are 10 up to 15 records inserted with various sites.
The list of sites is quite limited and consists of around 50 items.

Then I have following query

SELECT SITE_ID, MAX(WORK_DATE)
FROM TSH
GROUP BY 1

to get the latest entry for each site

What indexes should I create to get this query as quickest as possible?
Currently I have around 5000 records in the table.

Thanks in advance
Marcin