Have u tried df.saveAsParquetFIle? I think that method is on df Api Hth Marco On 19 Mar 2016 7:18 pm, "Vincent Ohprecio" <ohpre...@gmail.com> wrote:
> > For some reason writing data from Spark shell to csv using the `csv > package` takes almost an hour to dump to disk. Am I going crazy or did I do > this wrong? I tried writing to parquet first and its fast as normal. > > On my Macbook Pro 16g - 2.2 GHz Intel Core i7 -1TB the machine CPU's goes > crazy and it sounds like its taking off like a plane ... lol > > Here is the code if anyone wants to experiment: > > // ./bin/spark-shell --packages com.databricks:spark-csv_2.11:1.4.0 > > // > > // version 2.0.0-SNAPSHOT > > // Using Scala version 2.11.7 (Java HotSpot(TM) 64-Bit Server VM, Java > 1.7.0_80) > > // http://stat-computing.org/dataexpo/2009/the-data.html > > > def time[R](block: => R): R = { > > val t0 = System.nanoTime() > > val result = block // call-by-name > > val t1 = System.nanoTime() > > println("Elapsed time: " + (t1 - t0) + "ns") > > result > > } > > > val df = > sqlContext.read.format("com.databricks.spark.csv").option("header", > "true").load("/Users/employee/Downloads/2008.csv") > > val df_1 = df.withColumnRenamed("Year","oldYear") > > val df_2 = > df_1.withColumn("Year",df_1.col("oldYear").cast("int")).drop("oldYear") > > def convertColumn(df: org.apache.spark.sql.DataFrame, name:String, > newType:String) = { > > val df_1 = df.withColumnRenamed(name, "swap") > > df_1.withColumn(name, df_1.col("swap").cast(newType)).drop("swap") > > } > > val df_3 = convertColumn(df_2, "ArrDelay", "int") > > val df_4 = convertColumn(df_2, "DepDelay", "int") > > > // test write to parquet is fast > > df_4.select("Year", > "Cancelled").write.format("parquet").save("yearAndCancelled.parquet") > > > val selectedData = df_4.select("Year", "Cancelled") > > > > val howLong = > Time(selectedData.write.format("com.databricks.spark.csv").option("header", > "true").save("output.csv")) > > > //scala> val howLong = > time(selectedData.write.format("com.databricks.spark.csv").option("header", > "true").save("output.csv")) > > //Elapsed time: 3488272270000ns > > //howLong: Unit = () > > https://gist.github.com/bigsnarfdude/581b780ce85d7aaecbcb > > > > >
