240 发简信
IP属地:河北
  • 大佬,有入门的资料吗?

    flowable 流程引擎总结

    最近公司使用Flowable开发了自己的OA系统,因此对Flowable的相关内容进行如下总结 一、Flowable 是什么 目前最新版是Flowable 6.4.2(201...

  • 我们现在也要用这个 以前没接触过 请问怎么样开始😭

  • 我也觉得是这样,但是我去面试的时候说DataFrame是DataSet的子集,面试官惊讶(他觉得我说的是错的)

    RDD、DataFrame和DataSet的区别

    spark 2.X开始,三者的关系发生了变化,可以参考《且谈Apache Spark的API三剑客:RDD、DataFrame和Dataset》 ,在2.X中DataFram...

  • 我有个疑问:
    官网原文
    A DataFrame is a Dataset organized into named columns. It is conceptually equivalent to a table in a relational database or a data frame in R/Python, but with richer optimizations under the hood. DataFrames can be constructed from a wide array of sources such as: structured data files, tables in Hive, external databases, or existing RDDs. The DataFrame API is available in Scala, Java, Python, and R. In Scala and Java, a DataFrame is represented by a Dataset of Rows. In the Scala API, DataFrame is simply a type alias of Dataset[Row]. While, in Java API, users need to use Dataset<Row> to represent a DataFrame.
    其中两句:
    DataFrame is represented by a Dataset of Rows
    A DataFrame is a Dataset organized into named columns
    意思是不是DataFrame是DataSet的子集,而不是DataSet是DataFrame的特例?