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  1. Hive
  2. HIVE-4160 Vectorized Query Execution in Hive
  3. HIVE-4681

Fix ORC TimestampTreeReader.nextVector() to handle milli-nano math corectly

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Details

    • Fix ORC TimestampTreeReader to sum the second and nanosecond fraction timestamp vectors correctly
    • vectorization

    Description

      The current TimestampTreeReader implementation is broken when fed only milliseconds.

      If TS = 222ms.

         result.vector[i] = ... // == 0;
   nanoVector.vector[i] = ... // == 222000000
   if (result.vector[i] >= 0) {
     result.vector[i] += nanoVector.vector[i] / 1000000; // 222
   }
...
   result.vector[i] = (result.vector[i] * 1000000)
                + nanoVector.vector[i];
   // result.vector[i] == 444000000

      which is broken.

      This is not a problem in the Timestamp case, because 

      ts.setTime(222);        // {time=0; nanos=222000000}
ts.setNanos(222000000); // {time=0; nanos=222000000}

      Since that is not additive, the error does not occur in the regular ORC reader.

      Attachments

        1. HIVE-4681-001.patch
          3 kB
          Gopal Vijayaraghavan

        Issue Links

          relates to

          Sub-task - The sub-task of the issue HIVE-4884 ORC TimestampTreeReader.nextVector() off by a second when time in fractional

          • Major - Major loss of function.
          • Resolved

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              gopalv Gopal Vijayaraghavan
              gopalv Gopal Vijayaraghavan
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                Created:
                Updated:
                Resolved: