On 29/08/2013 18:31, Alexandre Benson Smith wrote: > > Em 29/8/2013 12:17, Tim Ward escreveu: > > But I thought Superserver used threads? And threads can run on > > separate CPUs? (Processes are an address space thing, not a CPU thing.) > > There are threads, but in fact they are "serialized", perhaps it's just > an over simplification, I don't know FB internals, but the threads does > not run in parallel (FB 3.0 will fix that). If you have a multi core > server (wich is an obvious thing theses days) you should prefer Classic > Server, the only case where I think SuperServer will be a choice is when > you have just one connection per database. > So Superserver is in effect single threaded and will use only a fraction of the power of even one of today's modest desktop PCs let alone a server - thanks, this wasn't obvious to me from the documentation. > > Perhaps you have automatic sweep disabled (check with gstat -h), if you > have sweep disabled the garbage will acumulate, so when a query need to > "scan" the table it will pay the cost to clean it up. I am not saying to > use automatic sweep, since it could trigger in the middle of the day > generating an "unknown" slowdown... What I suggest is that you keep > automatic sweep disabled and run a manual sweep (gfix -sweep) during off > peak hours. > Automatic sweep is indeed disabled, but "manual sweep during off peak hours" isn't practical. The system can need to run flat out for a couple of days at a time, and the problem arises after only a few hours.
-- Tim Ward [Non-text portions of this message have been removed]
