spark etl sample, attempt #1

dataframe.scala

import java.text.SimpleDateFormat
import java.util.Date

import org.apache.spark.{SparkContext, SparkConf}
import org.apache.spark.sql.{SaveMode, Row, SQLContext}
import com.databricks.spark.csv.CsvSchemaRDD
import org.apache.spark.sql.functions._



object JDBCTester {
  def main(args: Array[String]) {
    val conf = new SparkConf().setAppName("JDBC Tester")
    val sc = new SparkContext(conf)
    val sqlCtx = new SQLContext(sc)
    import sqlCtx.implicits._


    val volumes = sqlCtx.load("com.databricks.spark.csv", Map("path" -> "/home/ramp/tmp/volumes.data", "header" -> "false")).toDF("CREATED_AT",
      "UPDATED_AT",
      "DELETED_AT",
      "DELETED",
      "ID",
      "EC2_ID",
      "USER_ID",
      "PROJECT_ID",
      "HOST",
      "SIZE",
      "AVAILABILITY_ZONE",
      "INSTANCE_UUID",
      "MOUNTPOINT",
      "ATTACH_TIME",
      "STATUS",
      "ATTACH_STATUS",
      "SCHEDULED_AT",
      "LAUNCHED_AT",
      "TERMINATED_AT",
      "DISPLAY_NAME",
      "DISPLAY_DESCRIPTION",
      "PROVIDER_LOCATION",
      "PROVIDER_AUTH",
      "SNAPSHOT_ID",
      "VOLUME_TYPE_ID",
      "SOURCE_SYSTEM_NAME",
      "SOURCE_VOLID",
      "bootable",
      "attached_host",
      "provider_geometry",
      "_name_id",
      "encryption_key_id",
      "migration_status").as('V)
    val volume_type = sqlCtx.load("com.databricks.spark.csv", Map("path" -> "/home/ramp/tmp/volume_types.data", "header" -> "false")).toDF(
      "CREATED_AT","UPDATED_AT","DELETED_AT","DELETED","ID","NAME","SOURCE_SYSTEM_NAME", "DC").as('VT)

    val description_ = udf((source: String, name:String) => s"$name in $source datacenter")
    val instanceType = udf( () => "cbs")
    val keyGenerator = udf( () => 0)
    val getdate = udf( () => new SimpleDateFormat("dd/mm/yy").format(new java.util.Date()))
    val instance = udf( () => "m_Dim_Instance")
    val source_system = udf( () => "cbs_instance")
    val current_record = udf( () => 1)
    val extended_table = udf( () => "Dim_Instance_Extended_CBS")

    volumes.join(volume_type, $"VT.ID" === $"V.VOLUME_TYPE_ID", "inner")
      .select(
        keyGenerator() as 'Instance_Key,
        $"V.ID" as 'Instance_NK,
        instanceType() as 'Instance_Type,
        $"V.ID" as 'Assigned_Instance_Number,
        'PROJECT_ID as 'Assigned_Account_Number,
        'DISPLAY_NAME as 'Instance_Name,
        description_($"V.SOURCE_SYSTEM_NAME", 'NAME) as 'Instance_Description,
        'STATUS as 'Instance_Status,
        $"V.SOURCE_SYSTEM_NAME" as 'Instance_Datacenter,
        getdate() as 'Rec_Created_Date,
        getdate() as 'Rec_Updated_Date,
        $"V.CREATED_AT" as 'Instance_Creation_Date,
        $"V.UPDATED_AT" as 'Instance_Update_Date,
        instance() as 'Instance_Created_by,
        instance() as 'Instance_Updated_by,
        $"V.CREATED_AT" as 'Effective_Start_Datetime,
        $"V.DELETED_AT" as 'Effective_End_Datetime,
        source_system() as 'Source_System_Name,
        current_record() as 'Current_Record,
        extended_table() as 'Extended_Table_Name
      ).save("com.databricks.spark.csv", SaveMode.Overwrite, Map("path" -> "/home/ramp/tmp/dim"))

  }
}

scd_type2.scala

import java.text.SimpleDateFormat
import java.util.Date

import org.apache.spark.{SparkContext, SparkConf}
import org.apache.spark.sql.{SaveMode, Row, SQLContext}
import com.databricks.spark.csv.CsvSchemaRDD
import org.apache.spark.sql.functions._



object JDBCTester {
  def main(args: Array[String]) {
    val conf = new SparkConf().setAppName("JDBC Tester")
    val sc = new SparkContext(conf)
    val sqlCtx = new SQLContext(sc)
    import sqlCtx.implicits._

    val new_dim = sqlCtx.load("com.databricks.spark.csv", Map("path" -> "/home/ramp/tmp/new_dim.csv", "header" -> "true")).as('ndim)
    val ext_dim = sqlCtx.load("com.databricks.spark.csv", Map("path" -> "/home/ramp/tmp/ext_dim.csv", "header" -> "true")).as('pdim)

    val res = new_dim.join(ext_dim, new_dim("nk") === ext_dim("nk"), "inner")
    val now = new SimpleDateFormat().format(new Date())

    // scd type 2 changes
    val scd2 = res.filter($"ndim.t2" !== $"pdim.t2").flatMap( row => {
      val (newRowSeq, prevRowSeq) = row.toSeq.splitAt(row.length / 2)
      val (newRow, prevRow) = (
        Row.fromSeq(newRowSeq),
        Row.fromSeq(prevRowSeq.updated(6, now).updated(7, 0))
      )
      Array(prevRow, newRow)
    })
    // scd type 1 changes
    val scd1 = res.filter($"ndim.t1" !== $"pdim.t1").select($"ndim.*")

    sqlCtx.createDataFrame(scd2, scd1.schema).unionAll(scd1).saveAsCsvFile("/home/ramp/tmp/dim.csv")
  }
}

sql.scala

import java.text.SimpleDateFormat
import java.util.Date

import org.apache.spark.{SparkContext, SparkConf}
import org.apache.spark.sql.{SaveMode, Row, SQLContext}
import com.databricks.spark.csv.CsvSchemaRDD
import org.apache.spark.sql.functions._


object JDBCTester {
  def main(args: Array[String]) {
    val conf = new SparkConf().setAppName("JDBC Tester")
    val sc = new SparkContext(conf)
    val sqlCtx = new SQLContext(sc)


    val volumes = sqlCtx.load("com.databricks.spark.csv", Map("path" -> "/home/ramp/tmp/volumes.data", "header" -> "false")).toDF("CREATED_AT",
      "UPDATED_AT",
      "DELETED_AT",
      "DELETED",
      "ID",
      "EC2_ID",
      "USER_ID",
      "PROJECT_ID",
      "HOST",
      "SIZE",
      "AVAILABILITY_ZONE",
      "INSTANCE_UUID",
      "MOUNTPOINT",
      "ATTACH_TIME",
      "STATUS",
      "ATTACH_STATUS",
      "SCHEDULED_AT",
      "LAUNCHED_AT",
      "TERMINATED_AT",
      "DISPLAY_NAME",
      "DISPLAY_DESCRIPTION",
      "PROVIDER_LOCATION",
      "PROVIDER_AUTH",
      "SNAPSHOT_ID",
      "VOLUME_TYPE_ID",
      "SOURCE_SYSTEM_NAME",
      "SOURCE_VOLID",
      "bootable",
      "attached_host",
      "provider_geometry",
      "_name_id",
      "encryption_key_id",
      "migration_status")
    val volume_type = sqlCtx.load("com.databricks.spark.csv", Map("path" -> "/home/ramp/tmp/volume_types.data", "header" -> "false")).toDF(
      "CREATED_AT","UPDATED_AT","DELETED_AT","DELETED","ID","NAME","SOURCE_SYSTEM_NAME", "DC")

    sqlCtx.udf.register("description_" , (source: String, name:String) => s"$name in $source datacenter")
    sqlCtx.udf.register("instanceType" ,  () => "cbs")
    sqlCtx.udf.register("keyGenerator" ,  () => 0)
    sqlCtx.udf.register("getdate" ,  () => new SimpleDateFormat("dd/mm/yy").format(new java.util.Date()))
    sqlCtx.udf.register("instance" ,  () => "m_Dim_Instance")
    sqlCtx.udf.register("source_system" ,  () => "cbs_instance")
    sqlCtx.udf.register("current_record" ,  () => 1)
    sqlCtx.udf.register("extended_table" ,  () => "Dim_Instance_Extended_CBS")

    volume_type.registerTempTable("VT")
    volumes.registerTempTable("V")

    val stmt =
      """
        |SELECT
        | keyGenerator() as Instance_Key,
        | V.ID as Instance_NK,
        | instanceType() as Instance_Type,
        | V.ID as Assigned_Instance_Number,
        | V.PROJECT_ID as Assigned_Account_Number,
        | V.DISPLAY_NAME as Instance_Name,
        | description_(V.SOURCE_SYSTEM_NAME, VT.NAME) as Instance_Description,
        | V.STATUS as Instance_Status,
        | V.SOURCE_SYSTEM_NAME as Instance_Datacenter,
        | getdate() as Rec_Created_Date,
        | getdate() as Rec_Updated_Date,
        | V.CREATED_AT as Instance_Creation_Date,
        | V.UPDATED_AT as Instance_Update_Date,
        | instance() as Instance_Created_by,
        | instance() as Instance_Updated_by,
        | V.CREATED_AT as Effective_Start_Datetime,
        | V.DELETED_AT as Effective_End_Datetime,
        | source_system() as Source_System_Name,
        | current_record() as Current_Record,
        | extended_table() as Extended_Table_Name
        |FROM
        | V INNER JOIN VT ON
        |  V.VOLUME_TYPE_ID = VT.ID
      """.stripMargin

    sqlCtx.sql(stmt).save("com.databricks.spark.csv", SaveMode.Overwrite, Map("path" -> "/home/ramp/tmp/dim"))

  }
}

Hy can you explain me, what filter on "nk" column do?
What nk column is?

same to 'ndim.t2?