WordPress SQL performance problem

I have a new WordPress installation which I installed as a development environment. We had WP e-commerce installed with an incomplete store with about 450 products. But I decided not to use WP e-commerce and uninstalled it, and deleted all of the posts and pages that were associated with that store. Now the WP installation is pretty basic and with a small number of posts and almost no pages. But the performance on the c/panel (backend) is extremely slow and on the front end is slow. I believe that there are probably remains of clutter in the SQL database, or a poorly designed SQL DB, left over from the WP e-commerce store installation. Project is to solve the performance problem either by cleaning up the SQL database or fixing the SQL database or re-installing WP with a clean installation so I can re-upload what little content there is and start all over again. One complication is that there are multiple SQL databases on the server and a live/production website (Prostores sopping cart) on the root directory of the domain, and you must not disturb that SQL database. Our hosting company insisted upon doing the WP installation the first time, because they said that if the placement and configuration of the SQL database was not done correctly, it would interfere with the SQL database of the production website in the root directory: So you must be very careful about that and not change the position/location/basic configuration of the SQL server: I think the best solution is to re-install WP using the exact same position/location/basic configuration of the SQL server.