[jira] [Created] (HIVE-7072) HCatLoader only loads first region of hbase table

["Sushanth Sowmyan (JIRA)" <ji...@apache.org>]

Sushanth Sowmyan created HIVE-7072:
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             Summary: HCatLoader only loads first region of hbase table
                 Key: HIVE-7072
                 URL: https://issues.apache.org/jira/browse/HIVE-7072
             Project: Hive
          Issue Type: Bug
    Affects Versions: 0.14.0
            Reporter: Sushanth Sowmyan
            Assignee: Sushanth Sowmyan


Pig needs a config parameter 'pig.splitCombination' set to 'false' for it to be able to read HBaseStorageHandler-based tables.

This is done in the HBaseLoader at getSplits time, but HCatLoader does not do so, which results in only a partial data load.

Thus, we need one more special case definition in HCat, that sets this parameter in the job properties if we detect that we're loading a HBaseStorageHandler based table. The primary issue is one of where this code should go, since it doesn't belong in pig (pig does not know what loader behaviour should be, and this parameter is its interface to a loader), and doesn't belong in the HBaseStorageHandler either, since that's implementing a HiveStorageHandler and is connecting up the two. Thus, this should belong to HCatLoader. However, HCatLoader can't set it at an appropriate input-time, since it does not have knowledge of what the underlying format is at the time it needs to set that. Setting this parameter across the board results in poor performance for HCatLoader, so it must only be set when using with HBase.

Thus, it belongs in the SpecialCases definition as that was created specifically for these kinds of odd cases.





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