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  1. Blazegraph (by SYSTAP)
  2. BLZG-1249

Native memory implementation of ORDER BY

    Details

    • Type: Bug
    • Status: Open
    • Resolution: Unresolved
    • Affects Version/s: BLAZEGRAPH_RELEASE_1_5_1
    • Fix Version/s: None
    • Component/s: Query Engine
    • Labels:
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      Description

      This is a feature request to support ORDER BY on the native heap. The ordering for SPARQL is defined over a set of data types and any given variable in the ORDER BY may take on different data types for different bindings. This makes ORDER BY significantly less easy to implement when compared to standard external memory sorts, e.g., for SQL. Giving this, my inclination is to support a partitioned-by-datatype ordering followed by an iterator that visits the partitions in the partial ordering defined by the SPARQL specification. Of course, the ORDER BY clause can have multiple variables so this needs to be a nested series of partitioned sorts.

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          • Assignee:
            Unassigned
            Reporter:
            bryanthompson bryanthompson
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            Dates

            • Created:
              Updated: