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Apache Spark commented on SPARK-35439: -------------------------------------- User 'viirya' has created a pull request for this issue: https://github.com/apache/spark/pull/32586 > Use LinkedHashMap as the map of equivalent expressions to preserve insertion > order > ---------------------------------------------------------------------------------- > > Key: SPARK-35439 > URL: https://issues.apache.org/jira/browse/SPARK-35439 > Project: Spark > Issue Type: Improvement > Components: SQL > Affects Versions: 3.0.2, 3.1.1, 3.2.0 > Reporter: L. C. Hsieh > Assignee: L. C. Hsieh > Priority: Minor > > EquivalentExpressions maintains a map of equivalent expressions. It is > HashMap now so the insertion order is not guaranteed to be preserved later. > Subexpression elimination relies on retrieving subexpressions from the map. > If there is child-parent relationships among the subexpressions, we want the > child expressions come first than parent expressions, so we can replace child > expressions in parent expressions with subexpression evaluation. > Although we add expressions recursively into the map with depth-first > approach, when we retrieve the map values, it is not guaranteed that the > order is preserved. We should use LinkedHashMap for this usage. -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org