On Mon, Nov 2, 2015 at 10:33 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.
Sure. Or we could just keep calling it the visibility map, and then everyone would know what we're talking about. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers