Need more speed from this.

I hope someone can help me out with this.

Postgres 7.1.3
Solaris 2.8

I have a table called system_data setup like this.

| server_id | date | time | data_type_id | data |
|___________|________|________|______________|______|
| | | | | |
| 26 | a date | a time | 8 | 98 |
| | | | | |
-----------------------------------------------------

This table is indexed on server_id and data_type_id.

It currently has about 674,456 rows and is growing on a daily
basis.

The problem is that selects from this table are really slow.

For instance if I do this.

SELECT AVG(data) FROM system_data
WHERE date BETWEEN CAST('2001-02-01' AS DATE)
AND CAST ('2001-02-28' AS DATE)
AND
server_id = 26
AND
data_type_id = 8;

It will take several seconds to complete this select.

I need this type of data retrieval to be much faster if
possible.

Thanks in advance for any assistance.