Do these optimizations have any affect on database software? I know call overhead shows up as a performance bottleneck, but do these others optimizations also measurably improve performance?
--------------------------------------------------------------------------- Simon Riggs wrote: > This technique and others are discussed in detail in the Intel > Optimization Manual: > http://apps.intel.com/scripts-util/download.asp?url=/design/PentiumII/manuals/24512701.pdf&title=Intel%AE+Architecture+Optimization+Reference+Manual&fullpg=3&site=Developer > > Similar manual exists for AMD and other architectures. > > On Thu, 2005-12-08 at 23:07 -0500, Qingqing Zhou wrote: > > I write a program try to simulate it, but I am not good at micro > > optimization, and I just get a very weak but kind-of-stable improvement. I > > wonder if any people here are interested to take a look. > > You may be trying to use the memory too early. Prefetched memory takes > time to arrive in cache, so you may need to issue prefetch calls for N > +2, N+3 etc rather than simply N+1. > > p.6-11 covers this. > > There's a lot of papers around coming up with interesting sounding > techniques. AFAICS, all they've done is read the optimization guide and > tried to apply that wisdom, so it seems a good idea to go back to the > source. > > I think many of these techniques are generic across architectures, so > there is much to be done in this area, IMHO. Though we must respect > portability and confirm any tuning through testing. > > Best Regards, Simon Riggs > > > ---------------------------(end of broadcast)--------------------------- > TIP 5: don't forget to increase your free space map settings > -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
