daveg wrote: > On Mon, Feb 13, 2006 at 02:59:43PM -0500, Bruce Momjian wrote: > > Tom Lane wrote: > > > Bruce Momjian <email@example.com> writes: > > > > Tom Lane wrote: > > > >> More to the point, the utility of the patch remains unproven. > > > >> We are not in the habit of adding OS dependencies on speculation. > > > > > > > He ran tests, though it is speculation because non-caching is a pretty > > > > hard thing to find a benefit from except under low memory situations. > > > > > > Well, the tests (a) didn't show any particularly good speedup, and > > > (b) were not on the platforms that this is speculated to be useful on > > > (ie, those without O_DIRECT). > > > > > > I really don't think that an adequate case has been made for adding > > > a new OS dependency. > > > > Well, I think the patch should be applied, and the submitter does too, > > so unless I hear other votes, it is going in. > > I vote no for whatever that is worth. A "performance" change needs to > actually demonstrate improved performance. If the change is really > desireable to clean up some messy code, then add it as a cleanup change > without the extra system calls. Otherwise it just adds one more bit of > mystery for future maintainers who may be decieved into thinking that posix > advise calls are important voodoo.
Yes, your vote counts very much. What if I apply the patch, but mark the posix_advise() call in a NOT_USED macro block, so it will be ready for people to test, but will not be used until we are sure. -- Bruce Momjian | http://candle.pha.pa.us firstname.lastname@example.org | (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: 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