On Tue, Aug 27, 2024 at 7:22 PM Matthias van de Meent <boekewurm+postg...@gmail.com> wrote: > On Tue, 27 Aug 2024 at 23:40, Peter Geoghegan <p...@bowt.ie> wrote: > > Right, "trivial". Except in that it requires inventing a whole new > > general purpose infrastructure. > > Which seems to be in the process of being invented already elsewhere.
None of this stuff about implementation details really matters if there isn't agreement on what actual user-visible behavior we want. We're very far from that right now. > > Meanwhile, Tom is arguing against even > > showing this very basic information in EXPLAIN ANALYZE.You see the > > problem? > > I think Tom's main issue is additional clutter when running just plain > `explain analyze`, and he'd probably be fine with it if this was gated > behind e.g. VERBOSE or a new "get me the AM's view of this node" > -flag. I'm not at all confident that you're right about that. > > I mean it literally works in exactly the same way! It's literally > > indistinguishable to users, and works in a way that's consistent with > > historical behavior/definitions. > > Historically, no statistics/explain-only info is stored in the > IndexScanDesc, all data inside that struct is relevant even when > EXPLAIN was removed from the codebase. The same is true for > TableScanDesc Please try to separate questions about user-visible behavior from questions about the implementation. Here you're answering a point I'm making about user visible behavior with a point about where the counter goes. It's just not relevant. At all. > Now, you want to add this metadata to the struct. I'm quite hesitant > to start walking on such a surface, as it might just be a slippery > slope. I don't know why you seem to assume that it's inevitable that we'll get a huge amount of similar EXPLAIN ANALYZE instrumentation, of which this is just the start. It isn't. It's far from clear that even something like my patch will get in. > > Seems completely unrelated. > > I'd call "exposing function's pgstat data in explain" at least > somewhat related to "exposing indexes' pgstat data in explain". Not in any practical sense. -- Peter Geoghegan
