Dan Hecht has posted comments on this change. Change subject: IMPALA-5713: always reserve memory for preaggs ......................................................................
Patch Set 3: (2 comments) http://gerrit.cloudera.org:8080/#/c/7739/3/fe/src/main/java/org/apache/impala/planner/AggregationNode.java File fe/src/main/java/org/apache/impala/planner/AggregationNode.java: PS3, Line 327: 16b should we add a static_assert to backend to update this if needed, or you think it doesn't matter enough? Line 330: perInstanceMinReservation = (bufferSize + 64 * 1024) * PARTITION_FANOUT; this means we end up reserving around the same amount of memory for streaming pre-agg, right? wasn't one of the points of streaming pre-agg to help when under memory pressure? should we set a smaller bufferSize for streaming preagg? since they won't spill anyway, the buffer size shouldn't matter that much for perf, right? hmm, except for TLB, I guess. -- To view, visit http://gerrit.cloudera.org:8080/7739 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: I2b544f9ec1a906719e2bbb074743926b95a3a573 Gerrit-PatchSet: 3 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Tim Armstrong <tarmstr...@cloudera.com> Gerrit-Reviewer: Dan Hecht <dhe...@cloudera.com> Gerrit-Reviewer: Tim Armstrong <tarmstr...@cloudera.com> Gerrit-HasComments: Yes
