Huge Data

Hi,

I use PostgreSQL 7.4 for storing huge amount of data. For example 7 
million rows. But when I run the query "select count(*) from table;", it 
results after about 120 seconds. Is this result normal for such a huge 
table? Is there any methods for speed up the querying time? The huge 
table has integer primary key and some other indexes for other columns.

The hardware is: PIII 800 MHz processor, 512 MB RAM, and IDE hard disk 
drive.

-sezai