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  1. HPCC
  2. HPCC-19035

Use __builtin_prefetch when expanding hash tables

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    Details

    • Type: Improvement
    • Status: Resolved
    • Priority: Minor
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 7.0.0
    • Component/s: JLib
    • Labels:
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      Description

      When hash tables get large, the entries tend to be distributed across memory.  prefetching the next row should speed up expansion.

      Initial investigation with the code generator showed a ~1% speed up for a complex query.

       

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            • Assignee:
              ghalliday Gavin Halliday
              Reporter:
              ghalliday Gavin Halliday
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              • Created:
                Updated:
                Resolved: