2015-12-24 3:23 GMT+01:00 Michael Paquier <michael.paqu...@gmail.com>:
> On Thu, Dec 17, 2015 at 6:45 PM, Shulgin, Oleksandr > <oleksandr.shul...@zalando.de> wrote: > > On Wed, Dec 16, 2015 at 8:39 PM, Tomas Vondra < > tomas.von...@2ndquadrant.com> > > wrote: > >> On 12/01/2015 10:34 AM, Shulgin, Oleksandr wrote: > >>> > >>> > >>> I have the plans to make something from this on top of > >>> pg_stat_statements and auto_explain, as I've mentioned last time. The > >>> next iteration will be based on the two latest patches above, so it > >>> still makes sense to review them. > >>> > >>> As for EXPLAIN ANALYZE support, it will require changes to core, but > >>> this can be done separately. > >> > >> I'm re-reading the thread, and I have to admit I'm utterly confused what > >> is the current plan, what features it's supposed to provide and whether > it > >> will solve the use case I'm most interested in. Oleksandr, could you > please > >> post a summary explaining that? > >> > >> My use case for this functionality is debugging of long-running queries, > >> particularly getting EXPLAIN ANALYZE for them. In such cases I either > can't > >> run the EXPLAIN ANALYZE manually because it will either run forever > (just > >> like the query) and may not be the same (e.g. due to recent ANALYZE). > So we > >> need to extract the data from the process executing the query. > >> > >> I'm not essentially opposed to doing this in an extension (better an > >> extension than nothing), but I don't quite see how you could to do that > from > >> pg_stat_statements or auto_explain. AFAIK both extensions merely use > hooks > >> before/after the executor, and therefore can't do anything in between > (while > >> the query is actually running). > >> > >> Perhaps you don't intend to solve this particular use case? Which use > >> cases are you aiming to solve, then? Could you explain? > > > > Thanks for your interest in this patch! > > > > My motivation is the same as your use case: having a long-running query, > be > > able to look inside this exact query run by this exact backend. > > > > I admit the evolution of ideas in this patch can be very confusing: we > were > > trying a number of different approaches, w/o thinking deeply on the > > implications, just to have a proof of concept. > > It's great to see ideas of concepts and things to help address those > issues, at least we are agreeing that there is a hole in the > instrumentation and that it would be nice to fill it with something. > Still, it is not completely clear which approach would be taken. Is it > fair to mark the current patch as returned with feedback then? > +1 Pavel > -- > Michael >
