Hi Abshiek Group by performance can be improved by the following 1)enabling map side aggregation. In latest versions it is enabled by default SET hive.map.aggr = true;
2)Is there a data skew observed in some of the reducers? If so a better performance can be yielded by setting the following property SET hive.groupby.skewindata=true; Regards, Bejoy KS ________________________________ From: Abhishek <abhishek.dod...@gmail.com> To: Hive <user@hive.apache.org> Sent: Wednesday, September 26, 2012 10:31 PM Subject: How to optimize a group by query Hi all, I have written a query with group by clause, it is consuming lot of time is there any way to optimize this any configuration property or some thing. Regards Abhi Sent from my iPhone
