On Mon, Oct 21, 2019 at 2:15 PM Pavel Stehule <pavel.stehule@gmail.com> wrote: > > po 21. 10. 2019 v 10:25 odesílatel Amit Kapila <amit.kapila16@gmail.com> napsal: >> >> >> Sorry, but I am not able to understand the reason. Are you worried >> about the comments atop CountOtherDBBackends which says it is used in >> Drop Database and related commands? > > > no, just now the code in dropdb looks like > > if (force) > TerminateOtherDBBackends(...); > > CountOtherDBBackends(...); > > if I call CountOtherDBBackends from TerminateOtherDBBackends, then code will look like > > if (force) > TerminateOtherDBBackends(...); > else > CountOtherDBBackends(...); > > That looks like CountOtherDBBackends is not called when force clause is active. And this is not true. >
Hmm, can't we pass force as a parameter to TerminateOtherDBBackends() and then take the decision inside that function? That will make the code of dropdb function a bit simpler.
I don't think so it is correct. Because without FORCE flag, you should not to call TeminateOtherDBBackend ever.
Maybe I don't understand what is wrong.
if (force)
terminate();
CountOtherDBBackends()
if (some numbers)
ereport(ERROR, ..
This is fully correct for me.
> So I prefer current relations between routines. > > > >> >> > But I can (and I have not any problem with it) remove or significantly decrease sleeping time in TerminateOtherDBBackends. >> > >> > 100 ms is maybe very much - but zero is maybe too low. If there will not be any time between TerminateOtherDBBackends and CountOtherDBBackends, then probably CountOtherDBBackends hit waiting 100ms. >> > >> > What about only 5 ms sleeping in TerminateOtherDBBackends? >> > >> >> I am not completely sure about what is the most appropriate thing to >> do, but I favor removing sleep from TerminateOtherDBBackends. OTOH, >> there is nothing broken with the logic. Anyone else wants to weigh in >> here? > > > ok. But when I remove it, should not be better to set waiting in CountOtherDBBackends to some smaller number than 100ms? >
CountOtherDBBackends is called from other places as well, so I don't think it is advisable to change the sleep time in that function. Also, I don't want to add a parameter for it. I think you have a point that in some cases we might end up sleeping for 100ms when we could do with less sleeping time, but I think it is true to some extent today as well. I think we can anyway change it in the future if there is a problem with the sleep timing, but for now, I think we can just call CountOtherDBBackends after sending SIGTERM and call it good. You might want to add a futuristic note in the code.
ok.
I removed sleeping from TerminateOtherDBBackends().
If you want to change any logic there, please, do it without any hesitations. Maybe I don't see, what you think.