In response to Mark Mielke <mark@xxxxxxxxxxxxxx>: > Bill Moran wrote: > > In response to Mark Mielke <mark@xxxxxxxxxxxxxx>: > > > > > >> Bill Moran wrote: > >> > >>> I'm fairly sure that FreeBSD's GEOM does. Of course, it couldn't be doing > >>> consistency checking at that point. > >>> > >> According to this: > >> > >> http://www.freebsd.org/cgi/man.cgi?query=gmirror&apropos=0&sektion=8&manpath=FreeBSD+6-current&format=html > >> > >> There is a -b (balance) option that seems pretty clear that it does not > >> read from all drives if it does not have to: > >> > > > > >From where did you draw that conclusion? Note that the "split" algorithm > > (which is the default) divides requests up among multiple drives. I'm > > unclear as to how you reached a conclusion opposite of what the man page > > says -- did you test and find it not to work? > > > Perhaps you and I are speaking slightly different languages? :-) When I > say "does not read from all drives", I mean "it will happily read from > any of the drives to satisfy the request, and allows some level of > configuration as to which drive it will select. It does not need to read > all of the drives to satisfy the request." Ahh ... I did misunderstand you. -- Bill Moran Collaborative Fusion Inc. http://people.collaborativefusion.com/~wmoran/ wmoran@xxxxxxxxxxxxxxxxxxxxxxx Phone: 412-422-3463x4023 ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
