Anonymous Coward #248 has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/9693 )

Change subject: IMPALA-5842: Write page index in Parquet files
......................................................................


Patch Set 6:

(2 comments)

I have 2 minor findings only. Otherwise, LGTM. (I'm not an Impala nor a C/C++ 
expert, though.)

http://gerrit.cloudera.org:8080/#/c/9693/6/be/src/exec/hdfs-parquet-table-writer.cc
File be/src/exec/hdfs-parquet-table-writer.cc:

http://gerrit.cloudera.org:8080/#/c/9693/6/be/src/exec/hdfs-parquet-table-writer.cc@727
PS6, Line 727:   // max_values_ and mark the values as valid. In case min and 
max values are not
It is a bit misleading to by talking about marking the min/max values 
valid/invalid. It is about the null pages which case the min/max values do not 
make sense so we store empty strings instead.


http://gerrit.cloudera.org:8080/#/c/9693/6/be/src/exec/parquet-column-stats.inline.h
File be/src/exec/parquet-column-stats.inline.h:

http://gerrit.cloudera.org:8080/#/c/9693/6/be/src/exec/parquet-column-stats.inline.h@54
PS6, Line 54:         if (MinMaxTrait<T>::Compare(prev_page_max_value_, 
cs->max_value_) == 1 ||
I know it is not Java but it might be readable to use a java-like contract for 
compare. It says compare(a, b) < 0 if a < b etc.
It also might have performance benefit in some cases if you simply return a - b 
instead of if-else.



--
To view, visit http://gerrit.cloudera.org:8080/9693
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: Icbacf7fe3b7672e3ce719261ecef445b16f8dec9
Gerrit-Change-Number: 9693
Gerrit-PatchSet: 6
Gerrit-Owner: Zoltan Borok-Nagy <[email protected]>
Gerrit-Reviewer: Anonymous Coward #248
Gerrit-Reviewer: Csaba Ringhofer <[email protected]>
Gerrit-Reviewer: Lars Volker <[email protected]>
Gerrit-Reviewer: Tim Armstrong <[email protected]>
Gerrit-Reviewer: Zoltan Borok-Nagy <[email protected]>
Gerrit-Comment-Date: Tue, 27 Mar 2018 12:32:29 +0000
Gerrit-HasComments: Yes

Reply via email to