*at such = at such scale Вт, 9 марта 2021 г. в 11:01, Vladimir Ozerov <[email protected]>:
> Hi Jihoon, > > I would say that 5 sec could be actually a pretty good result at such. Did > you have a chance to check which exact rules contributed to the planning > time? You may inject a listener to VolcanoPlanner to check that. > > Regards, > Vladimir > > Вт, 9 марта 2021 г. в 05:37, Jihoon Son <[email protected]>: > >> Hi all, >> >> I posted the same question on the ASF slack channel, but am posting >> here as well to get a quicker response. >> >> I'm seeing an issue in query planning that it takes a long time (+5 >> sec) for a giant union query that has 120 subqueries in it. I captured >> a flame graph (attached in this email) to see where the bottleneck is, >> and based on the flame graph, I believe the query planner spent most >> of time to explore the search space of candidate plans to find the >> best plan. This seems because of those many subqueries in the same >> union query. Is my understanding correct? If so, for this particular >> case, it seems possible to parallelize exploring the search space. Do >> you have any plan for parallelizing this part? I'm not sure whether >> it's already done though in the master branch. I tried to search for a >> jira ticket on https://issues.apache.org/jira/browse/CALCITE, but >> couldn't find anything with my search skill. >> >> Thanks, >> Jihoon >> >
