Ron Hu created SPARK-22164:
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Summary: support histogram in estimating the cardinality of
aggregate (or group-by) operator
Key: SPARK-22164
URL: https://issues.apache.org/jira/browse/SPARK-22164
Project: Spark
Issue Type: Sub-task
Components: SQL
Affects Versions: 2.2.0
Reporter: Ron Hu
Histogram is effective in dealing with skewed distribution. After we generate
histogram information for column statistics, we need to adjust aggregate (or
group-by) cardinality estimation based on equi-height histogram information.
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