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Namit Jain commented on HIVE-1900: ---------------------------------- 1. Why should it be any different than sort-merge join ? ExecMapper needs to keep track of the current file, and then change the partitioning columns whenever the file changes 2. Why should it matter ? 3. Why should it matter ? > a mapper should be able to span multiple partitions > --------------------------------------------------- > > Key: HIVE-1900 > URL: https://issues.apache.org/jira/browse/HIVE-1900 > Project: Hive > Issue Type: Improvement > Components: Query Processor > Reporter: Namit Jain > Assignee: He Yongqiang > > Currently, a mapper only spans a single partition which creates a problem in > the presence of many > small partitions (which is becoming a common usecase in facebook). > If the plan is the same, a mapper should be able to span files across > multiple partitions -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.