[ https://issues.apache.org/jira/browse/IMPALA-7637?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
bharath v reassigned IMPALA-7637: --------------------------------- Assignee: Yongzhi Chen > Include more hash table stats in profile > ---------------------------------------- > > Key: IMPALA-7637 > URL: https://issues.apache.org/jira/browse/IMPALA-7637 > Project: IMPALA > Issue Type: Improvement > Components: Backend > Reporter: Tim Armstrong > Assignee: Yongzhi Chen > Priority: Major > Labels: observability, ramp-up > > Our hash table collects some useful stats about collisions and travel length, > but then we don't do anything to expose them: > https://github.com/apache/impala/blob/540611e863fe99b3d3ae35f8b94a745a68b9eba2/be/src/exec/hash-table.h#L989 > We should add some of them to the profile, maybe: > * the number of probes > * the average travel length per probe > * the number of hash collisions > * (optional) the number of hash table resizes. We already have the hash table > size and the resize time, which I think is sufficient to debug most problems > with resizes. -- 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