Remus Rusanu created HIVE-16790: ----------------------------------- Summary: HiveCostModel.JoinAlgorithm and derivatives abuse RelMetadataQuery.instance Key: HIVE-16790 URL: https://issues.apache.org/jira/browse/HIVE-16790 Project: Hive Issue Type: Bug Components: Query Planning Reporter: Remus Rusanu Assignee: Remus Rusanu
Calling {{RelMetadataQuery.instance()}} has serious performance implication, as it invalidates the memoization cache used in Calcite, see HIVE-16757 {{HiveCostModel.JoinAlgorithm}} and the derivate classes abuse this calls, sometimes multiple times per function. All methods in JoinAlgortihm that need a RelMetadataQuery should accept it as argument, not build one instance. -- This message was sent by Atlassian JIRA (v6.3.15#6346)