Do I Need A DBMS or Data Warehouse??

Hi, We are experiencing, what I seem to think, very poor performance. We need to do a ot of look-ups and reports. We don't need to do a lot of inputs, or data/order entry. I was thinking that maybe we need to take a data warehouse or DSS approach. I have been told that conventional DBMSes are good at accomodating a lot of transactions ("getting data into the system"), but not good at letting information get extracted. Any opnions here? Thank you! Chris