Really old thread now, but just to add a little bit to John's answer, logical reads should be the first thing to try to tune. It *might* not have a big impact on some queries on low traffic servers, compared to physical reads which are more costly, but as queries get more complex, and the load and concurrency starts to grow, logical reads start to result in more resources needed to process queries. That's because clearly the more data you need to process, the more time it will take, and if you start adding up many queries being executed at the same time, the load on the server can grow considerably. The data will also take more space, which should be less of a problem nowadays, with memory being so cheap.