On 2020-Nov-24, Tom Lane wrote: > I'm inclined to go ahead and commit the 0001 patch I posted at [1] > (ie, change the implementation of GUC_REPORT to avoid intra-query > reports), since that addresses a performance problem that's > independent of the goal here. The rest of this seems to still > be in Greg's court.
Sounded a good idea to me. > Has anyone got an opinion about the further improvement I suggested: > > >> As it stands, 0001 reduces the ParameterStatus message traffic to > >> at most one per GUC per query, but it doesn't attempt to eliminate > >> duplicate ParameterStatus messages altogether. We could do that > >> as a pretty simple adjustment if we're willing to expend the storage > >> to remember the last value sent to the client. It might be worth > >> doing, since for example the function-SET-clause case would typically > >> lead to no net change in the GUC's value by the end of the query. > > On reflection this seems worth doing, since excess client traffic > is far from free. Agreed. If this is just a few hundred bytes of server-side local memory per backend, it seems definitely worth it.
