[jira] [Created] (SPARK-18457) ORC and other columnar formats using HiveShim read all columns when doing a simple count

["Andrew Ray (JIRA)" <ji...@apache.org>]

Andrew Ray created SPARK-18457:
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             Summary: ORC and other columnar formats using HiveShim read all columns when doing a simple count
                 Key: SPARK-18457
                 URL: https://issues.apache.org/jira/browse/SPARK-18457
             Project: Spark
          Issue Type: Bug
          Components: SQL
    Affects Versions: 2.0.2, 1.6.3
         Environment: Hadoop 2.7.0
            Reporter: Andrew Ray
            Priority: Minor


Doing a `select count(*) from a_orc_table` reads all columns and thus is slower than a query selecting one like `select count(a_column) from a_orc_table`. Data read can be seen in the UI (appears to only be accurate for Hadoop 2.5+ based on comment in FileScanRDD.scala line 80).

I will create a PR shortly.



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