Single user versus multiple users

You must take the presence of other users into consideration before trying to solve a database problem, especially if those users are using the same network.

Since most networks can transfer only one packet at a time, many users may be delayed while a large transfer is in progress. Such a delay may cause locks to be held longer, which causes even more delays.

When response time is “abnormally” high, and normal tests indicate no problem, it could be due to other users on the same network. In such cases, ask the user when the process was being run, if the operating system was generally sluggish, if other users were doing large transfers, and so on.

In general, consider multiuser impacts, such as the delay caused by a long transaction, before digging more deeply into the database system to solve an abnormal response time problem.