Matthew Wakeling wrote: > On Fri, 16 May 2008, Tom Lane wrote: > > One additional point: this means that one transaction in every 32K > > writing transactions *does* have to do extra work when it assigns itself > > an XID, namely create and zero out the next page of pg_clog. And that > > doesn't just slow down the transaction in question, but the next few > > guys that would like an XID but arrive on the scene while the > > zeroing-out is still in progress. > > > > This probably contributes to the behavior that Simon and Josh regularly > > complain about, that our transaction execution time is subject to > > unpredictable spikes. I'm not sure how to get rid of it though. > > Does it really take that long to zero out 8kB of RAM? I thought CPUs were > really quick at doing that! Yea, that was my assumption too. -- Bruce Momjian <bruce@xxxxxxxxxx> http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. +
