EZSPA-698: Fix review comments

Author: YegorMaksymchuk

examples/spark-3.2.0/apps/src/main/scala/com/hpe/examples/spark/sql/SqlOnGpuExample.scala

@@ -7,138 +7,18 @@ object SqlOnGpuExample {
   def main(args: Array[String]): Unit = {
     val spark = SparkSession.builder()
       .getOrCreate()
+    val sc = spark.sparkContext
 
-    simpleSelect(spark)
-    crossJoin(spark)
-    leftJoin(spark)
-    whereSelect(spark)
-    unionSelect(spark)
-    filesInteraction(spark)
-    spark.stop()
-  }
-
-  def simpleSelect(spark: SparkSession): Unit = {
-    println("SIMPLE SELECT")
     import spark.implicits._
+
     val viewName = "df"
-    val df = Seq(1, 2, 3).toDF("value")
+    val df = sc.parallelize(Seq(1, 2, 3)).toDF("value")
     df.createOrReplaceTempView(viewName)
 
     spark.sql(s"SELECT value FROM $viewName WHERE value <>1").explain()
     spark.sql(s"SELECT value FROM $viewName WHERE value <>1").show()
-  }
-
-  def crossJoin(spark: SparkSession): Unit = {
-    println("CROSS JOIN")
-    import spark.implicits._
-
-    val sc = spark.sparkContext
-    val recordsAmount = 50
-
-
-    val df1 = sc.parallelize(1 to recordsAmount, 1)
-      .toDF("test")
-
-    val df2 = sc.parallelize(recordsAmount to recordsAmount * 2, 1)
-      .toDF("test")
-
-    df1.crossJoin(df2).sample(0.1).explain()
-    df1.crossJoin(df2).sample(0.1).show()
-  }
-
-  def leftJoin(spark: SparkSession): Unit = {
-    println("LEFT JOIN")
-
-    import spark.implicits._
-    val firstViewName = "leftJoinFirst"
-    val secondViewName = "leftJoinSecond"
-
-    Seq((1, "test1"), (2, "test2"), (3, "test3"))
-      .toDF("key", "string")
-      .createTempView(firstViewName)
-
-    Seq((1, "test4"), (4, "test5"), (2, "test6"))
-      .toDF("key", "string")
-      .createTempView(secondViewName)
-
-
-    val df = spark.sql(s"SELECT * FROM $firstViewName LEFT JOIN " +
-      s"leftJoinSecond ON $firstViewName.key=$secondViewName.key")
-
-    df.explain()
-    df.show()
-
-  }
-
-  def whereSelect(spark: SparkSession): Unit = {
-    println("WHERE SELECT")
-
-    import spark.implicits._
-
-
-    val whereSelectView = "whereSelectView"
-    Seq(
-      (1, "first"),
-      (2, "second"),
-      (3, "third")
-    ).toDF("key", "string")
-      .createTempView(whereSelectView)
-
-    val df = spark.sql(s"SELECT * FROM $whereSelectView WHERE key >= 2")
-
-    df.explain()
-    df.show()
-  }
-
-  def unionSelect(spark: SparkSession): Unit = {
-    println("UNION SELECT")
-
-    import spark.implicits._
-
-    val firstDF = Seq(
-      (1, "first"),
-      (2, "second"),
-      (3, "third")
-    ).toDF("key", "string")
-
-    val secondDF = Seq(
-      (100, "John"),
-      (200, "Mike"),
-      (300, "Bob")
-    ).toDF("age", "name")
-
-    val resultDF = firstDF.union(secondDF)
-
-    resultDF.explain()
-    resultDF.show()
-  }
-
-  def filesInteraction(spark: SparkSession): Unit = {
-    println("FILES INTERACTION")
-    import spark.implicits._
-    val pathPrefix = s"/tmp/filesInteraction${System.currentTimeMillis()}"
-
-    Set("parquet", "orc", "json").foreach(
-      format => {
-        println(format)
-        println("Write")
-        val path = s"$pathPrefix$format"
-        (1 to 100)
-          .toDF("val")
-          .write
-          .format(format)
-          .save(path)
-
-        println("Read")
-        val df = spark.read
-          .format(format)
-          .load(path)
-          .filter($"val" >= 95)
-        df.explain()
-        df.show()
-      }
-    )
 
+    spark.stop()
   }
 
 }