Xuefu Zhang created HIVE-5298:
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             Summary: AvroSerde performance problem caused by HIVE-3833
                 Key: HIVE-5298
                 URL: https://issues.apache.org/jira/browse/HIVE-5298
             Project: Hive
          Issue Type: Improvement
          Components: Query Processor
    Affects Versions: 0.11.0
            Reporter: Xuefu Zhang
            Assignee: Xuefu Zhang
             Fix For: 0.13.0


HIVE-3833 fixed the targeted problem and made Hive to use partition-level 
metadata to initialize object inspector. In doing that, however, it goes thru 
every file under the table to access the partition metadata, which is very 
inefficient, especially in case of multiple files per partition. This causes 
more problem for AvroSerde because AvroSerde initialization accesses schema, 
which is located on file system. As a result, before hive can process any data, 
it needs to access every file for a table, which can take long enough to cause 
job failure because of lack of job progress.

The improvement can be made so that partition metadata is only access once per 
partition.

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