Alex Behm has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/8085 )

Change subject: IMPALA-5307: part 1: don't transfer disk I/O buffers out of 
parquet
......................................................................


Patch Set 6:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/8085/6//COMMIT_MSG
Commit Message:

http://gerrit.cloudera.org:8080/#/c/8085/6//COMMIT_MSG@44
PS6, Line 44: There is a significant regression (50% increase in runtime) in
Do we understand where the regression comes from exactly? Somehow I find it 
hard to believe a 50% overhead just from copying. Is it maybe another tcmalloc 
issue where different threads allocate/free the memory? Have you tried a 
similar experiment with MT_DOP?



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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I767c1e2dabde7d5bd7a4d5c1ec6d14801b8260d2
Gerrit-Change-Number: 8085
Gerrit-PatchSet: 6
Gerrit-Owner: Tim Armstrong <[email protected]>
Gerrit-Reviewer: Alex Behm <[email protected]>
Gerrit-Reviewer: Dan Hecht <[email protected]>
Gerrit-Reviewer: Lars Volker <[email protected]>
Gerrit-Reviewer: Tim Armstrong <[email protected]>
Gerrit-Comment-Date: Wed, 27 Sep 2017 15:34:38 +0000
Gerrit-HasComments: Yes

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