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https://issues.apache.org/jira/browse/SPARK-15856?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Cheng Lian updated SPARK-15856:
-------------------------------
    Description: 
In Spark 2.0, after unifying Datasets and DataFrames, we made two API breaking 
changes:

# {{DataFrameReader.text()}} now returns {{Dataset\[String\]}} instead of 
{{DataFrame}}
# {{SQLContext.range()}} now returns {{Dataset\[java.lang.Long\]}} instead of 
{{DataFrame}}

However, these two changes introduced several inconsistencies and problems:

# {{spark.read.text()}} silently discards partitioned columns when reading a 
partitioned table in text format since {{Dataset\[String\]}} only contains a 
single field. Users have to use {{spark.read.format("text").load()}} to 
workaround this, which is pretty confusing and error-prone.
# All data source shortcut methods in `DataFrameReader` return {{DataFrame}} 
(aka {{Dataset\[Row\]}}) except for {{DataFrameReader.text()}}.
# When applying typed operations over Datasets returned by {{spark.range()}}, 
weird schema changes may happen. Please refer to SPARK-15632 for more details.

Due to these reasons, we decided to revert these two changes.

  was:
In Spark 2.0, after unifying Datasets and DataFrames, we made two API breaking 
changes:

# {{DataFrameReader.text()}} now returns {{Dataset\[String\]}} instead of 
{{DataFrame}}
# {{SQLContext.range()}} now returns {{Dataset\[java.lang.Long\]}} instead of 
{{DataFrame}}

However, these two changes introduced several inconsistencies and problems:

# {{spark.read.text()}} silently discards partitioned columns when reading a 
partitioned table in text format since {{Dataset\[String\]}} only contains a 
single field. Users have to use {{spark.read.format("text").load()}} to 
workaround this, which is pretty confusing and error-prone.
# All data source shortcut methods in `DataFrameReader` returns a {{DataFrame}} 
(aka {{Dataset\[Row\]}} except for {{DataFrameReader.text()}}.
# When applying typed operations over Datasets returned by {{spark.range()}}, 
weird schema changes may happen. Please refer to SPARK-15632 for more details.

Due to these reasons, we decided to revert these two changes.


> Revert API breaking changes made in DataFrameReader.text and SQLContext.range
> -----------------------------------------------------------------------------
>
>                 Key: SPARK-15856
>                 URL: https://issues.apache.org/jira/browse/SPARK-15856
>             Project: Spark
>          Issue Type: Sub-task
>          Components: SQL
>            Reporter: Cheng Lian
>
> In Spark 2.0, after unifying Datasets and DataFrames, we made two API 
> breaking changes:
> # {{DataFrameReader.text()}} now returns {{Dataset\[String\]}} instead of 
> {{DataFrame}}
> # {{SQLContext.range()}} now returns {{Dataset\[java.lang.Long\]}} instead of 
> {{DataFrame}}
> However, these two changes introduced several inconsistencies and problems:
> # {{spark.read.text()}} silently discards partitioned columns when reading a 
> partitioned table in text format since {{Dataset\[String\]}} only contains a 
> single field. Users have to use {{spark.read.format("text").load()}} to 
> workaround this, which is pretty confusing and error-prone.
> # All data source shortcut methods in `DataFrameReader` return {{DataFrame}} 
> (aka {{Dataset\[Row\]}}) except for {{DataFrameReader.text()}}.
> # When applying typed operations over Datasets returned by {{spark.range()}}, 
> weird schema changes may happen. Please refer to SPARK-15632 for more details.
> Due to these reasons, we decided to revert these two changes.



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