impala-reviews mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Tim Armstrong (Code Review)" <ger...@cloudera.org>
Subject [Impala-ASF-CR] IMPALA-5586: Null-aware anti-join can take a long time to cancel
Date Fri, 14 Jul 2017 22:43:28 GMT
Tim Armstrong has posted comments on this change.

Change subject: IMPALA-5586: Null-aware anti-join can take a long time to cancel
......................................................................


Patch Set 3:

(2 comments)

http://gerrit.cloudera.org:8080/#/c/7393/3/be/src/exec/partitioned-hash-join-node.cc
File be/src/exec/partitioned-hash-join-node.cc:

Line 1018:   // For each row, iterate over all rows in the build table.
The need for RETURN_IF_CANCELLED is a little subtle. A one-line comment would be useful, e.g.
"This loop can run for a long time. Periodically check for cancellation."


Line 1023:     for (int j = 0; j < build_rows->num_rows(); ++j) {
This loop can also potentially run for a long time if build_rows is large. It will be a bit
expensive to check every iteration but maybe check every 1024 rows or something like that
(I'm suggesting a power-of-two because computing % is cheap for a constant power-of-two).

  if (j % 1024 == 0) RETURN_IF_CANCELLED(state);


-- 
To view, visit http://gerrit.cloudera.org:8080/7393
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-MessageType: comment
Gerrit-Change-Id: I0800754d4ad31cbadbdfadc630c640963f3f6053
Gerrit-PatchSet: 3
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: anujphadke <aphadke@cloudera.com>
Gerrit-Reviewer: Thomas Tauber-Marshall <tmarshall@cloudera.com>
Gerrit-Reviewer: Tim Armstrong <tarmstrong@cloudera.com>
Gerrit-Reviewer: anujphadke <aphadke@cloudera.com>
Gerrit-HasComments: Yes

Mime
View raw message