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Lars Volker reassigned IMPALA-5004: ----------------------------------- Assignee: Sahil Takiar > Switch to sorting node for large TopN queries > --------------------------------------------- > > Key: IMPALA-5004 > URL: https://issues.apache.org/jira/browse/IMPALA-5004 > Project: IMPALA > Issue Type: Improvement > Components: Frontend > Affects Versions: Impala 2.9.0 > Reporter: Lars Volker > Assignee: Sahil Takiar > Priority: Major > > As explained by [~tarmstrong] in IMPALA-4995: > bq. We should also consider switching to the sort operator for large limits. > This allows it to spill. The memory requirements for TopN also are > problematic for large limits, since it would allocate large vectors that are > untracked and also require a large amount of contiguous memory. > There's already logic to select TopN vs. Sort: > [planner/SingleNodePlanner.java#L289|https://github.com/apache/incubator-impala/blob/master/fe/src/main/java/org/apache/impala/planner/SingleNodePlanner.java#L289] -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-all-unsubscr...@impala.apache.org For additional commands, e-mail: issues-all-h...@impala.apache.org