We ran into an interesting performance issue a few weeks back. We had migrated our primary fileserver over to a new machine (it was previously running on the same machine as our website). We expected some of the pages on our website to be a bit slower since the files were no longer on the same box (we have both data in VFP and in SQL Server 2005), but some of them were suddenly painfully slow. They went from 1-2 seconds to more than 7+ seconds. We talked about installing a dedicated network card to link two servers to help, but it still didn't seem like the performance should take that much of a hit.

My boss spent some time tracing the problem and found it was really slow when we opened the company file from our accounting system (Sage Pro). I've talked about the performance of USE in the past, but it was still amazing to see how slow it was. He tried using a mapped drive and UNC mapping but the performance of each was about the same. This particular table is part of a database, so he tried prefixing the USE statement with the database name, ex. USE F:\PathTo\Data\MyDatabase!MyTable IN 0 - the difference was amazing. That 7+ seconds dropped back down to 1-2 seconds: a bit slower than it was when it was local, but still much faster than it had been. Resolving the database is apparently very slow.