Github user brkyvz commented on a diff in the pull request:

    https://github.com/apache/spark/pull/5842#discussion_r29545291
  
    --- Diff: 
sql/core/src/main/scala/org/apache/spark/sql/execution/stat/StatFunctions.scala 
---
    @@ -77,4 +78,42 @@ private[sql] object StatFunctions {
           })
         counts.cov
       }
    +
    +  /** Generate a table of frequencies for the elements of two columns. */
    +  private[sql] def crossTabulate(df: DataFrame, col1: String, col2: 
String): DataFrame = {
    +    val tableName = s"${col1}_$col2"
    +    val distinctCol2 = 
df.select(col2).distinct.collect().sortBy(_.get(0).toString)
    --- End diff --
    
    That's what I did first. Xiangrui thought this would be more efficient.
    
    On Fri, May 1, 2015 at 10:16 PM, Reynold Xin <notificati...@github.com>
    wrote:
    
    > In
    > 
sql/core/src/main/scala/org/apache/spark/sql/execution/stat/StatFunctions.scala
    > <https://github.com/apache/spark/pull/5842#discussion_r29545262>:
    >
    > > @@ -77,4 +78,42 @@ private[sql] object StatFunctions {
    > >        })
    > >      counts.cov
    > >    }
    > > +
    > > +  /** Generate a table of frequencies for the elements of two columns. 
*/
    > > +  private[sql] def crossTabulate(df: DataFrame, col1: String, col2: 
String): DataFrame = {
    > > +    val tableName = s"${col1}_$col2"
    > > +    val distinctCol2 = 
df.select(col2).distinct.collect().sortBy(_.get(0).toString)
    >
    > btw - isn't a more efficient way to run this is to do groupBy(col1,
    > col2).count(), and then pivot the table?
    >
    > —
    > Reply to this email directly or view it on GitHub
    > <https://github.com/apache/spark/pull/5842/files#r29545262>.
    >



---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---

---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org

Reply via email to