Tim Armstrong has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/9002 )

Change subject: IMPALA-6383: free memory after skipping parquet row groups
......................................................................


Patch Set 1:

(4 comments)

http://gerrit.cloudera.org:8080/#/c/9002/1//COMMIT_MSG
Commit Message:

http://gerrit.cloudera.org:8080/#/c/9002/1//COMMIT_MSG@13
PS1, Line 13: Testing:
My feeling is that this testing is enough for now. With the reservation changes 
forthcoming, the multiple-row-group tests failed hard when it tried to allocate 
new buffers for the next row group when the buffers for the previous row group 
were released.

We could add a mem_limit test tuned to reproduce it but those have a tendency 
to be flaky and it doesn't seem worth the effort when more robust test coverage 
will be forthcoming.


http://gerrit.cloudera.org:8080/#/c/9002/1/be/src/exec/hdfs-parquet-scanner.h
File be/src/exec/hdfs-parquet-scanner.h:

http://gerrit.cloudera.org:8080/#/c/9002/1/be/src/exec/hdfs-parquet-scanner.h@647
PS1, Line 647:   /// were returned. and when returning the last batch.
> nit: remove "."?
Done


http://gerrit.cloudera.org:8080/#/c/9002/1/be/src/exec/hdfs-parquet-scanner.cc
File be/src/exec/hdfs-parquet-scanner.cc:

http://gerrit.cloudera.org:8080/#/c/9002/1/be/src/exec/hdfs-parquet-scanner.cc@623
PS1, Line 623:     // We skipped the previous row group. Release resources 
before starting another.
> This gets called for cases where no resources have been reserved (e.g. L655
I could also reorganise the code so that ReleaseSkippedRowGroupResources() gets 
called before "continue" so that it's more explicit. I was originally thinking 
that would be error-prone and easy to forget, but with the NumStreams() DCHECK 
maybe that won't be the case.


http://gerrit.cloudera.org:8080/#/c/9002/1/be/src/exec/hdfs-parquet-scanner.cc@738
PS1, Line 738:     col_reader->Close(row_batch);
> nit: while you're here you could reduce this to a single line.
Done



--
To view, visit http://gerrit.cloudera.org:8080/9002
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: Ibc2f8f27c9b238be60261539f8d4be2facb57a2b
Gerrit-Change-Number: 9002
Gerrit-PatchSet: 1
Gerrit-Owner: Tim Armstrong <[email protected]>
Gerrit-Reviewer: Lars Volker <[email protected]>
Gerrit-Reviewer: Michael Ho <[email protected]>
Gerrit-Reviewer: Tim Armstrong <[email protected]>
Gerrit-Comment-Date: Thu, 11 Jan 2018 19:16:43 +0000
Gerrit-HasComments: Yes

Reply via email to