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From daveoshinsky <...@git.apache.org>
Subject [GitHub] drill issue #517: DRILL-4704 fix
Date Wed, 13 Jul 2016 20:25:24 GMT
Github user daveoshinsky commented on the issue:

    https://github.com/apache/drill/pull/517
  
    Regarding Aman's last comment, please add the following... In the scenario addressed by
this fix, there is a const integer that came from the SQL select where clause, and that is
what is being casted into a decimal, for comparison with each a decimal value in each row.
  Since the integer is constant, a thoroughly optimized piece of code would cast it just once
to a decimal, and use the stored decimal to compare with the decimal value in each row.  It
appears that that is not what this code is doing. It is casting repeatedly, for each row.
 So, rather than be concerned with just a few added integer divisions by 10 (a small number
around log10(the const integer) + 1 divides), this code should ideally be (more) extensively
modified to do the cast operation just once.  That's too big a change for me to make for this
fix.  Besides, which is preferable?  Code that does not function properly (DRILL-4704), and
is not well optimized?  Or code that behaves correctly, and is only slightly 
 less well optimized?


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