mysql tablescan query causes iowait to shoot up
Basically if there is a table-scan query in mysql on a large table, then iowait shoots up (normal). But long after the query is done, iowait is still up there, and everything executes so very slowly. I look at iowait in TOP.
Please help. I can avoid table-scan for my end users (by careful eval of all queries), but I need to do ad-hoc queries once in a while. There must be a way to avoid this problem.
