I recommend: * Write the code you're worried about. * Test it. * If it's fast enough, don't worry about it. * If it's not, return to the first step and try something else.
Technical spikes answer questions in a more relevant way than general discussion. Clinton On Fri, Mar 13, 2009 at 10:46 AM, Ivan Bojer <ivan.bo...@citrix.com> wrote: > I am really trying to understand performance issues. I agree with you > that real-time apps will suffer, but if I am writing a controller for a get > plane I would not use any O/R mapping tool obviously. You really want to run > on bare metal there. > > So, real-time app definition is quite fuzzy and I personally think that it > is quite ambiguous term. Back to my question, we are actually working on > network policy appliance (think layer 7 packet switching). Can this qualify > as close to a real-time application. It depends if you ask network guy or > the application guy :) > > I think that we are close enough to worry about performance and to be > diligent to do anything that can speed up any layer of application (short of > going directly into assembly code :) ). > > This is the reason why I asked the question. If someone can tell me that > writing result maps will give me 10%,20%,30% performance improvement that > will tell me something. Beside all of this I am really just curious from the > geekness factor on why is there a difference. > > Thank you for your answer. > > > *From: *Kengkaj Sathianpantarit <kengka...@gmail.com> > *Reply-To: *IBatis <user-java@ibatis.apache.org> > *Date: *Fri, 13 Mar 2009 06:35:03 -0700 > *To: *IBatis <user-java@ibatis.apache.org> > *Subject: *Re: Java reflection performance > > > By realtime applications, I just mean applications that the timing is > really important. > From your example, for retrieving an account balance, the system slowdown > sometimes for 10 seconds is bad, but there is nobody dies or losses big > benefit because of it. > But for jet fighters, it's a different story. > > This is an off-topic, if you want discuss further, please discuss with me > via e-mail. > > Best Regards, > Kengkaj > > On Fri, Mar 13, 2009 at 8:16 PM, Chris O'Connell < > oconn...@gorillachicago.com> wrote: > > I'm curious what you mean by 'realtime application'. Not trying to be > confrontational, but do you mean like the difference between writing > controls for a jet fighter vs. retrieving an account balance? I've always > thought they were both 'realtime'. Just a difference in semantics, I'm > sure, but I am curious what you mean. > > Thanks, > Chris > > > On Fri, Mar 13, 2009 at 1:21 AM, Kengkaj Sathianpantarit < > kengka...@gmail.com> wrote: > > It is "slower", because it has more things to do, but if you're not > implementing realtime application, this should not be an issue. > > Kengkaj > > > On Fri, Mar 13, 2009 at 11:47 AM, Ivan Bojer <ivan.bo...@citrix.com> > wrote: > > Ibatis documentation states that there is performance gain if one uses > resultmaps instead of letting Ibatis figure out class mapping on its own. I > could not find any more info about why is this a case!? Can anyone elaborate > on this? Is this because reflection is slow in general? > > > > > > -- > -- > Chris O'Connell > Application Developer > Gorilla > 312.243.8777 x19 > > > >
