On Thu, Mar 29, 2018 at 7:55 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > I wrote: >> I have to go do something >> else right now, but I'll take a closer look at 0004 later. > > OK, so after studying 0004, it seems to me that we could do it more > simply as attached; that is, move the IndexFreeSpaceMapVacuum calls > into btvacuumscan/spgvacuumscan, do them only if we found any recyclable > pages, and drop the calls in btvacuumcleanup/spgvacuumcleanup altogether. > > The reason I think this is sufficient is that the scans find and record > every reusable page in the index, no matter whether they were recorded > before or not. Therefore, if we don't find any such pages, there's > nothing useful in the FSM and no particular urgency about making its > upper pages up-to-date. It's true that if the FSM is actually corrupt, > leaving that to be fixed retail by searches is probably less efficient > than doing an IndexFreeSpaceMapVacuum call would be --- but *only* if > you assume that the problem is just in the upper pages and the leaf > pages are all fine. That doesn't seem to be a case we should optimize > for.
+1, LGTM.
