Magnus Hagander wrote: > > > I'm hoping someone can shed some light on these results. > > > > Not without a lot more detail on how you *got* the results. > > What exactly did you do to force the various plan choices? > > (I see some ridiculous choices of indexscans, for instance, > > suggesting improper use of enable_seqscan in some cases.) > > And what's the "cache rows" and "disk rows" stuff, and how do > > you know that what you were measuring is actually what you > > think it is? I have zero confidence in Windows-atop-ATA as a > > platform for measuring disk-related behaviors, because I > > don't think you can control or even know what caching is going on. > > You can control the writeback-cache from Device Manager->(the > disk)->Policies. And if that is turned off, fsync definitly should write > through, just as on *nix. (write-cache is on by default, no surprise) > > AFAIK, you can't control what is cached for reading.
Are you saying that fsync() doesn't write to the platters by default on Win32? -- 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 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
