On Wed, Nov 4, 2015 at 12:19 PM, Amit Kapila <amit.kapil...@gmail.com> wrote: > On Wed, Nov 4, 2015 at 4:45 AM, Masahiko Sawada <sawada.m...@gmail.com> > wrote: >> >> On Tue, Nov 3, 2015 at 12:33 PM, Amit Kapila <amit.kapil...@gmail.com> >> wrote: >> > On Tue, Nov 3, 2015 at 5:04 AM, Robert Haas <robertmh...@gmail.com> >> > wrote: >> >> >> >> On Sat, Oct 31, 2015 at 1:32 AM, Amit Kapila <amit.kapil...@gmail.com> >> >> wrote: >> >> > >> >> > What is your main worry about changing the name of this map, is it >> >> > about more code churn or is it about that we might introduce new >> >> > issues >> >> > or is it about that people are already accustomed to call this map as >> >> > visibility map? >> >> >> >> My concern is mostly that I think calling it the "visibility and >> >> freeze map" is excessively long and wordy. >> >> >> >> One observation that someone made previously is that there is a >> >> difference between "all-visible" and "index-only scan OK". An >> >> all-visible page that has a HOT update is no longer all-visible (it >> >> needs vacuuming) but an index-only scan would still be OK (because >> >> only the non-indexed values in the tuple have changed, and every scan >> >> scan can see either the old or the new tuple but not both. At >> >> present, the index-only scan will consult the heap page anyway, >> >> because all we know is that the page is not all-visible. But maybe in >> >> the future somebody will decide to add a bit for that. Then we'd have >> >> the "visibility, usable for index-only scans, and freeze map", but I >> >> think "_vufiosfm" will not be a good choice for a file suffix. >> >> >> > >> > I think in that case we can call it as page info map or page state map, >> > but >> > I find retaining visibility map name in this case or for future (if we >> > want >> > to >> > add another bit) as confusing. In-fact if you find "visibility and >> > freeze >> > map", >> > as excessively long, then we can change it to "page info map" or "page >> > state >> > map" now as well. >> > >> >> In that case, file suffix would be "_pim" or "_psm"? > > Right. > >> IMO, "page info map" would be better, because the bit doesn't indicate >> the status of page in real time, it's just additional information. >> Also we need to rewrite to new name in source code, and source file >> name as well. >> > > I think so. Here I think the right thing to do is lets proceed with fixing > other issues of patch and work on this part later and in the mean time > we might get more feedback on this part of proposal. >
Yeah, I'm going to do that changes if there is no strong objection from hackers. Regards, -- Masahiko Sawada -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
