beliefer commented on a change in pull request #27428:
URL: https://github.com/apache/spark/pull/27428#discussion_r452133696



##########
File path: 
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/RewriteDistinctAggregates.scala
##########
@@ -118,7 +118,75 @@ import org.apache.spark.sql.types.IntegerType
  *       LocalTableScan [...]
  * }}}
  *
- * The rule does the following things here:
+ * Third example: single distinct aggregate function with filter clauses (in 
sql):
+ * {{{
+ *   SELECT
+ *     COUNT(DISTINCT cat1) FILTER (WHERE id > 1) as cat1_cnt,
+ *     COUNT(DISTINCT cat2) as cat2_cnt,
+ *     SUM(value) AS total
+ *  FROM
+ *    data
+ *  GROUP BY
+ *    key
+ * }}}
+ *
+ * This translates to the following (pseudo) logical plan:
+ * {{{
+ * Aggregate(
+ *    key = ['key]
+ *    functions = [COUNT(DISTINCT 'cat1) with FILTER('id > 1),
+ *                 COUNT(DISTINCT 'cat2),
+ *                 sum('value)]
+ *    output = ['key, 'cat1_cnt, 'cat2_cnt, 'total])
+ *   LocalTableScan [...]
+ * }}}
+ *
+ * This rule rewrites this logical plan to the following (pseudo) logical plan:
+ * {{{
+ *   Aggregate(

Review comment:
       This means to revert some code like
   
https://github.com/apache/spark/commit/d59e7195f6051820c95f84c83b01148975412d85#diff-8075628c8d39481271059f6fb2dd1e62L160
   ?




----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

For queries about this service, please contact Infrastructure at:
[email protected]



---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to