How to improve query performance?

I did up an online survey over the weekend, and its gotten a little on
the...slow side :(  Unfortunately, I can see where I can speed it up any,
so I'm asking for any suggestions, if its possible.

Explain on the query I'm using shows:

Sort  (cost=5455.34 size=0 width=0)
  ->  Aggregate  (cost=5455.34 size=0 width=0)
        ->  Group  (cost=5455.34 size=0 width=0)
              ->  Sort  (cost=5455.34 size=0 width=0)
                    ->  Seq Scan on op_sys  (cost=5455.34 size=39024 width=12)

The Query itself is:

my $OSlisting = "\
select count(sys_type) as tot_sys_type,sys_type \
  from op_sys \
 where sys_type is not null \
 group by sys_type \
 order by tot_sys_type desc;";

The table looks like:

Table    = op_sys
+----------------------------------+----------------------------------+-------+
|              Field               |              Type                | Length|
+----------------------------------+----------------------------------+-------+
| ip_number                        | text                             |   var |
| sys_type                         | text                             |   var |
| browser_type                     | text                             |   var |
| entry_added                      | datetime                         |     8 |
| probe                            | bool                             |     1 |
+----------------------------------+----------------------------------+-------+
Indices:  op_sys_ip
          op_sys_type

The table holds ~120k records right now, and the above query returns ~1100.

To get a feel for the speed it returns, see http://www.hub.org/OS_Survey

I can't think of any way to improve the speed, and yes, I do a 'vacuum
analyze' on it periodically (did one just before the above EXPLAIN)...

Other other note...its a v6.4.2 server, running on a PII with 384Meg of
RAM and FreeBSD 3.0-STABLE...


Marc G. Fournier
Systems Administrator @ hub.org
primary: scrappy@hub.org           secondary: scrappy@{freebsd|postgresql}.org