[ https://issues.apache.org/jira/browse/IMPALA-8834?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Tim Armstrong resolved IMPALA-8834. ----------------------------------- Fix Version/s: Impala 4.0 Resolution: Fixed > Investigate enabling safe version of OPTIMIZE_PARTITION_KEY_SCANS by default > ---------------------------------------------------------------------------- > > Key: IMPALA-8834 > URL: https://issues.apache.org/jira/browse/IMPALA-8834 > Project: IMPALA > Issue Type: Improvement > Components: Backend > Reporter: Tim Armstrong > Assignee: Tim Armstrong > Priority: Major > Labels: perf > Fix For: Impala 4.0 > > > Just an idea I had while updating the docs. We already have the logic in the > planner to determine when a partition key scan has "distinct" semantics - > i.e. you obtain the correct results so long as the scan returns 0 rows for a > partition when there are no rows present, and at least one row when there is > a row present (but the exact number doesn't affect correctness). > We could push this knowledge down into the scan nodes and have them terminate > early. This would be quite efficient if file handles and footers were already > cached and greatly reduce the number of rows flowing through the rest of the > plan. -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-all-unsubscr...@impala.apache.org For additional commands, e-mail: issues-all-h...@impala.apache.org