[ https://issues.apache.org/jira/browse/SPARK-6006?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Reynold Xin closed SPARK-6006. ------------------------------ Resolution: Fixed Assignee: Davies Liu Fix Version/s: 1.6.0 This is fixed as of Spark 1.6. > Optimize count distinct in case of high cardinality columns > ----------------------------------------------------------- > > Key: SPARK-6006 > URL: https://issues.apache.org/jira/browse/SPARK-6006 > Project: Spark > Issue Type: Improvement > Components: SQL > Affects Versions: 1.1.1, 1.2.1 > Reporter: Yash Datta > Assignee: Davies Liu > Priority: Minor > Fix For: 1.6.0 > > > In case there are a lot of distinct values, count distinct becomes too slow > since it tries to hash partial results to one map. It can be improved by > creating buckets/partial maps in an intermediate stage where same key from > multiple partial maps of first stage hash to the same bucket. Later we can > sum the size of these buckets to get total distinct count. -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org