group slow

DecimalHi people,


Is there any procedure to make the group function faster?
I mean, i have a tabel with 200.000 record and about 8 fields, a command like:
---
select username,count(*) from table group by username
---

will take about 4/5 secunds

a simple select count(*) from table

will take 0.00045 secunds ( more or less )

here's the table description:

+---------------+---------------+------+-----+---------------------+-------+
| Field         | Type          | Null | Key | Default             | Extra |
+---------------+---------------+------+-----+---------------------+-------+
| username      | varchar(255)  |      | MUL |                     |       |
| filename      | text          |      |     |                     |       |
| file_bytes    | bigint(15)    |      |     | 0                   |       |
| remote_host   | varchar(255)  |      |     |                     |       |
| remote_ip     | varchar(255)  |      |     |                     |       |
| command       | varchar(255)  |      |     |                     |       |
| transfer_time | decimal(12,5) |      |     | 0.00000             |       |
| date_time     | datetime      |      |     | 0000-00-00 00:00:00 |       |
| info          | varchar(2)    |      |     |                     |       |
+---------------+---------------+------+-----+---------------------+-------+


Jorge