RE: Update staistics Running Way Slow
<SNIP> >> 2. Couldnt he run one update statistics for each column? If they all started >> at the same time, they would be sharing the buffers which whoever is in >> the lead pulls in, but be able to run across multiple CPU's. Kind of like >> starting multiple batch jobs which process the same file sequentially on >> a multi cpu box... as long as your processes dont get out of sync you only >> do one disk read, the rest is cached. >> >> I dont have a big enough test box to test this theory, but thoughts on how >> this might perform would be appreciated. > >Not a bad idea, but what happens if they DO get out of sync? That disk >is going to get hammered! You are also relying on exclusive use of the >buffers, or at least no other users flushing your buffers. :-) > >Cheers, >-- >Mark. If you get out of sync, then life has the potential to suck some, I dont think that will be the case though. My reasons: 1. For the processes to get out of sync, read ahead has to be working well enough to mean that disk i/o is not a significant bottleneck. If that is the case, why not throw more processors at it .(Though you might need to watch for things to really start to suck) 2. From the look of his disk i/o he didnt really seem to be hitting any disks for more than 25%, so they could probably handle a bit more work. As far as the buffers go, with 400,000 buffers, I hope the turn over rate is not so high that I someone is going to take away my page before I get to it. If I get that far behind the lead guy is probably going to get far enough ahead of me to be hitting a different fragment most of the time. I could most definitely be wrong though. Nothing like a benchmark to straighten out people like me! Will ------------------------------------------------------------ This e-mail has been sent to you courtesy of OperaMail, as a free service from Opera Software, makers of the award-winning Web Browser, Opera. Visit us at http://www.opera.com/ or our portal at: http://www.myopera.com/ Your free e-mail account is waiting at: http://www.operamail.com/ ------------------------------------------------------------