Thomas Tauber-Marshall has posted comments on this change.

Change subject: IMPALA-2932: Extend DistributedPlanner to account for hash 
table build cost
......................................................................


Patch Set 3:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/4098/2/fe/src/main/java/com/cloudera/impala/planner/DistributedPlanner.java
File fe/src/main/java/com/cloudera/impala/planner/DistributedPlanner.java:

Line 461:             lhsTree.getCardinality() * 
ExchangeNode.getAvgSerializedRowSize(lhsTree));
> you're not guaranteed to have computed rhsDataSize at this point
Sorry about that.

It seems like this might be a bug with the existing code, though? Since it 
means that we don't do the hash table size check at line 489 in situations 
where we have a rhs cardinality estimate but no lhs num nodes, since we don't 
calculate the broadcast cost even though we could calculate the size of the rhs 
in this situation.

I submitted a new version with both of these things fixed, but of course I can 
do it a different way if it was intentional that we don't do the hash table 
size check for the broadcast in situations where we can't calculate the 
broadcast cost.


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Gerrit-MessageType: comment
Gerrit-Change-Id: I03a0f56f69c8deae68d48dfdb9dc95b71aec11f1
Gerrit-PatchSet: 3
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Thomas Tauber-Marshall <[email protected]>
Gerrit-Reviewer: Marcel Kornacker <[email protected]>
Gerrit-Reviewer: Matthew Jacobs <[email protected]>
Gerrit-Reviewer: Mostafa Mokhtar <[email protected]>
Gerrit-Reviewer: Thomas Tauber-Marshall <[email protected]>
Gerrit-HasComments: Yes

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