| DataFrame-class {SparkR} | R Documentation | 
DataFrames can be created using functions like
jsonFile, table etc.
dataFrame(sdf, isCached = FALSE) toRDD(x) groupedData(sgd)
| sdf | A Java object reference to the backing Scala DataFrame | 
| isCached | TRUE if the dataFrame is cached | 
envAn R environment that stores bookkeeping states of the DataFrame
sdfA Java object reference to the backing Scala DataFrame
jsonFile, table