[ic] Slow searches

[Company InterNet Services]

I have a database with 300,000 items online (will be expanded to 500,000)
Every time I search it takes around 2 minutes, whether alot of items are found or not.
I need this to be much faster... around 2 seconds

Currently it's on GDBM (the defult database type), My server has Postgress installed
(but I have never used it).

Is there a way to convert my current database into a faster type (so searches will appear faster.)
Or would be making seperate catelogs be better (breaking up the database), Would customers still be able to order different items
from different catelogs using one shopping cart?

Ken Lyons