We are constantly looking for new ways to speed up our online store and we have identified one major bottle neck, MySQL. osCommerce uses MySQL and only MySQL for it database backend.
The issue arises as MySQL gets overloaded with to many users running on the server at the same time and it begins to slow down. You can switch to another ISP, but over time MySQL will become over crowed again and slow down. We have seen this happen many times over the years we have been operating.
The other solution is to switch to another database like PostgreSQL and leave MySQL behind. Unfortunately, there is no patch available to move osCommerce over to PostgreSQL. Instead we have decided to set a long term gaol and port osCommerce to PostgreSQL.
We have already made many modifications to osCommerce in order to meet this goal.
Please feel free to contact us with any questions you may have.