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Namit Jain commented on HIVE-3552: ---------------------------------- https://reviews.facebook.net/D7029 > performant manner for performing cubes and rollups in case of less aggretation > ------------------------------------------------------------------------------ > > Key: HIVE-3552 > URL: https://issues.apache.org/jira/browse/HIVE-3552 > Project: Hive > Issue Type: New Feature > Components: Query Processor > Reporter: Namit Jain > Assignee: Namit Jain > > This is a follow up for HIVE-3433. > Had a offline discussion with Sambavi - she pointed out a scenario where the > implementation in HIVE-3433 will not scale. Assume that the user is performing > a cube on many columns, say '8' columns. So, each row would generate 256 rows > for the hash table, which may kill the current group by implementation. > A better implementation would be to add an additional stage - in the first > stage perform the group by assuming there was no cube. Ad another stage, where > you would perform the cube. The assumption is that the group by would have > decreased the output data significantly. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira