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From Kunal Khatua <kkha...@mapr.com>
Subject RE: Understanding the -Dbounds JVM option
Date Mon, 07 Aug 2017 20:01:07 GMT
I believe that flag was renamed

https://github.com/apache/drill/blob/master/exec/memory/base/src/main/java/org/apache/drill/exec/memory/BoundsChecking.java

I might not be the best person to answer this, but it involves enforcing the bounds checking
of value vectors so that Drill does not access offsets beyond the limits (i.e. bounds) of
value vectors.
By default, Drill will do bounds checking. Disabling will improve performance, but has the
potential risk of unsafe memory access which can crash a Drillbit.  

DRILL-5351 had a commit that reduced the number of checks, but couldn't eliminate the checks
entirely.



-----Original Message-----
From: Muhammad Gelbana [mailto:m.gelbana@gmail.com] 
Sent: Monday, August 07, 2017 4:38 AM
To: dev@drill.apache.org
Subject: Understanding the -Dbounds JVM option

This page <https://drill.apache.org/docs/configuring-drill-memory/> refers to a JVM
option by the name *bounds*. I tried googling for it but I couldn't find anything.

Would someone please elaborate on the effect of this option or post a link that does ?

Thanks,
Gelbana
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