Hello! I'm not sure that Ignite is able to detect actual affinity 100% of the time. So that's why collocate=true may help and that's why distributedJoins may slow down a perfectly collocated query.
Other than that, I don't think Ignite is going to beat Pg on group by performance right now, when there's a lot of data to process. Maybe consider using task-split instead of SQL for such case, you will still need to scan all data. Regards, -- Ilya Kasnacheev ср, 5 июн. 2019 г. в 05:37, David <[email protected]>: > Hi Ilya, > > thx for helping me > > the column is collocated. Still I need around ~10+Servers to match one PG > Server speed for a group by. > > What do you mean with use "collocated=true"? > I thought it is only needed in case you dont have collocated data and still > want to have full result set. > and its not needed when data are collocated. Do I understand it wrong? > > > btw side question: > when using sqlline.sh with the "distributedJoins=true" > all queries are x-times slower than without > > which makes totaly sense in case for non collocated data. > But it is also the case for collocated data, which makes no sense. > > sqlline.sh --verbose=true -u > jdbc:ignite:thin://127.0.0.1/?distributedJoins=true > > > > -- > Sent from: http://apache-ignite-users.70518.x6.nabble.com/ >
