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From zellerh <...@git.apache.org>
Subject [GitHub] trafodion pull request #1525: [TRAFODION-3028] Support CONTROL QUERY SHAPE (...
Date Thu, 19 Apr 2018 00:22:52 GMT
Github user zellerh commented on a diff in the pull request:

    https://github.com/apache/trafodion/pull/1525#discussion_r182605678
  
    --- Diff: core/sql/common/ExprNode.cpp ---
    @@ -737,6 +737,16 @@ NABoolean OperatorType::match(OperatorTypeEnum wildcard) const
     	      return FALSE;
     	    }
     
    +        case REL_ANY_EXTRACT:
    +	  switch (op_)
    +	    {
    +	    case REL_FAST_EXTRACT:
    --- End diff --
    
    Yes, this is for historical reasons. Khaled originally implemented a "fast extract" operator
that would take the output of a query and store it in a delimited HDFS file.
    
    Later, when we wanted to implement insert into Hive tables, someone recognized that the
fast extract operator did something very similar, so they enhanced it and internally used
it to implement Hive inserts. We could try to hide this by avoiding the term "FAST_EXTRACT",
and in fact this is done in EXPLAIN, but SHOWSHAPE still shows this heritage.



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