On Fri, Jul 8, 2022 at 3:50 AM Justin Pryzby <pry...@telsasoft.com> wrote: > > On Thu, Jul 07, 2022 at 04:21:37PM -0400, Robert Haas wrote: > > I mean, what I really want here if I'm honest is to not have the > > system divide the number of rows by the loop count. And it sort of > > sounds like maybe that's what you want, too. You want to know whether > > the loop count is actually zero, not whether it's close to zero when > > you divide it by some number that might be gigantic. > ... > > involves a dozen or two different nested loops, and if we didn't > > insist on dividing the time by the loop count, it would be MUCH EASIER > > to figure out whether the time spent in the Index Scan is a > > significant percentage of the total time or not. > > I think the guiding princible for what to do should be to reduce how much is > needed to explain about how to interpret what explain is showing... > > The docs say this: > | In such cases, the loops value reports the total number of executions of the > | node, and the actual time and rows values shown are averages per-execution. > | This is done to make the numbers comparable with the way that the cost > | estimates are shown. Multiply by the loops value to get the total time > | actually spent in the node. > > On Thu, Jul 07, 2022 at 01:45:19PM -0700, Peter Geoghegan wrote: > > Plus you could probably > > make some kind of concession in the direction of maintaining > > compatibility with the current approach if you had to. Right? > > The minimum would be to show the information in a way that makes it clear that > it's "new style" output showing a total and not an average, so that a person > who sees it knows how to interpret it (same for the web "explain tools") > > A concession would be to show the current information *plus* total/raw values. > > This thread is about how to display the existing values. >
I feel the discussion has slightly deviated which makes it unclear whether this patch is required or not? -- With Regards, Amit Kapila.
