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wangmeng commented on HIVE-964: ------------------------------- if the two join tables have the same big skew key on one value (for example ,select * from table A join B on A.id=b.id, both table A and B have a lot of keys on id=1, in this case ,map join will OOM), how to fix this case? Will it rollback to common join ? > handle skewed keys for a join in a separate job > ----------------------------------------------- > > Key: HIVE-964 > URL: https://issues.apache.org/jira/browse/HIVE-964 > Project: Hive > Issue Type: Improvement > Components: Query Processor > Reporter: Namit Jain > Assignee: He Yongqiang > Fix For: 0.6.0 > > Attachments: hive-964-2009-12-17.txt, hive-964-2009-12-28-2.patch, > hive-964-2009-12-29-4.patch, hive-964-2010-01-08.patch, > hive-964-2010-01-13-2.patch, hive-964-2010-01-14-3.patch, > hive-964-2010-01-15-4.patch > > > The skewed keys can be written to a temporary table or file, and a followup > conditional task can be used to perform the join on those keys. > As a first step, JDBM can be used for those keys -- This message was sent by Atlassian JIRA (v6.2#6252)