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Namit Jain commented on HIVE-1007: ---------------------------------- jar -xvf ./build/hadoopcore/hadoop-0.20.0/hadoop-0.20.0-core.jar Using hadoop.version 0.20.0, The following test works fine: t hive.input.format=org.apache.hadoop.hive.ql.io.CombineHiveInputFormat; DROP TABLE nullscript; CREATE TABLE nullscript(KEY STRING, VALUE STRING) STORED AS TEXTFILE; LOAD DATA LOCAL INPATH '../data/files/nullfile.txt' INTO TABLE nullscript; select transform(key) using '/bin/cat' as key1 from nullscript; DROP TABLE nullscript; and we can 1 split: [junit] 09/12/22 10:45:24 INFO io.CombineHiveInputFormat: number of splits 1 Seems like a hadoop bug > CombinedHiveInputFormat fails with empty input > ---------------------------------------------- > > Key: HIVE-1007 > URL: https://issues.apache.org/jira/browse/HIVE-1007 > Project: Hadoop Hive > Issue Type: Bug > Components: Query Processor > Affects Versions: 0.4.1 > Reporter: Dave Lerman > Assignee: Dave Lerman > Attachments: hive.1007.1.patch > > > In a multi-stage query, when one stage returns no data (resulting in a bunch > of output files with size 0), the next stage creates a job with 0 mappers > which just sits in the Hadoop task track forever and hangs the query at 0%. > The issue is that CombineHiveInputFormat looks for blocks to populate splits, > find nones (since input is all 0 bytes), and then returns an empty array from > getSplits. > There may be good a way to just skip that job altogether, but as a quick hack > to get it working, when there are no splits, I just create a single empty one > using the first path so that the job doesn't hang. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.