Marc mysqld runs on a very powerful Operton machine with 16GB memory and barely any other application process running, it is hard to believe that a simple select that runs under 2 second will utilize all the resources...that is why I tend to think there is something in the mysql set up that caused this...any idea where I should look?
BTW: the numbers are in milliseconds Thanks Haitao --- Marc Slemko <[EMAIL PROTECTED]> wrote: > On Mon, 7 Jun 2004, Haitao Jiang wrote: > > > > > Yes. The time I measure like I said is purely > around > > statement.execQuery() call. Connection creation is > not > > a factor here at all. > > > > My database has 1.64 million rows and 4 queries > are > > all selects, which are identical in both serial > and > > parallel cases. > > > > In serial cases: > > Query 0 took 590 > > Query 1 took 431 > > Query 2 took 461 > > Query 3 took 440 > > > > In parallel cases: > > Queryer 3 query took 1552 > > Queryer 1 query took 1632 > > Queryer 2 query took 1783 > > Queryer 0 query took 1923 > > > > I don't understand why in 4 concurrent connection > > cases (already created not included in the timing) > it > > takes more than 3 times longer to exec. a query. > > Umh... if your queries are limited by some > bottleneck on the server (such > as, for example, CPU) then why would running them in > parallel make it any > faster? > > It seems that in the sequential case they are taking > a total of 1922 > (whatever those units are) while in the parallel > case they are taking > 1923. What this is telling you is that, in this > case, a single query is > able to fully utilize the resources (likely CPU > given these numbers, > although it is possible it could be disk) on the > server. If a single > query can fully utilize the server, all that adding > more concurrency > can possibly do is slow the total throughput down. > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: > http://lists.mysql.com/[EMAIL PROTECTED] > __________________________________ Do you Yahoo!? Friends. Fun. Try the all-new Yahoo! Messenger. http://messenger.yahoo.com/ -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
