spark-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Sean Owen (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (SPARK-22725) df.select on a Stream is broken, vs a List
Date Thu, 07 Dec 2017 17:00:00 GMT

     [ https://issues.apache.org/jira/browse/SPARK-22725?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Sean Owen updated SPARK-22725:
------------------------------
    Priority: Minor  (was: Major)

> df.select on a Stream is broken, vs a List
> ------------------------------------------
>
>                 Key: SPARK-22725
>                 URL: https://issues.apache.org/jira/browse/SPARK-22725
>             Project: Spark
>          Issue Type: Bug
>          Components: Spark Core
>    Affects Versions: 2.3.0
>            Reporter: Andrew Ash
>            Priority: Minor
>
> See failing test at https://github.com/apache/spark/pull/19917
> Failing:
> {noformat}
>   test("SPARK-ABC123: support select with a splatted stream") {
>     val df = spark.createDataFrame(sparkContext.emptyRDD[Row], StructType(List("bar",
"foo").map {
>       StructField(_, StringType, false)
>     }))
>     val allColumns = Stream(df.col("bar"), col("foo"))
>     val result = df.select(allColumns : _*)
>   }
> {noformat}
> Succeeds:
> {noformat}
>   test("SPARK-ABC123: support select with a splatted stream") {
>     val df = spark.createDataFrame(sparkContext.emptyRDD[Row], StructType(List("bar",
"foo").map {
>       StructField(_, StringType, false)
>     }))
>     val allColumns = Seq(df.col("bar"), col("foo"))
>     val result = df.select(allColumns : _*)
>   }
> {noformat}
> After stepping through in a debugger, the difference manifests at https://github.com/apache/spark/blob/8ae004b4602266d1f210e4c1564246d590412c06/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/QueryPlan.scala#L120
> Changing {{seq.map}} to {{seq.toList.map}} causes the test to pass.
> I think there's a very subtle bug here where the {{Seq}} of column names passed into
{{select}} is expected to eagerly evaluate when {{.map}} is called on it, even though that's
not part of the {{Seq}} contract.



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org


Mime
View raw message