[Spark] Add Clustering example

Add Clustering example

Closes #2520

GitOrigin-RevId: 895b82e456dd1cd26c7e6b13d84f4ad4428b9913

examples/scala/src/main/scala/example/Clustering.scala

@@ -0,0 +1,61 @@
+/*
+ * Copyright (2021) The Delta Lake Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package example
+
+import org.apache.spark.sql.SparkSession
+
+object Clustering {
+
+  def main(args: Array[String]): Unit = {
+    val tableName = "deltatable"
+
+    val deltaSpark = SparkSession
+      .builder()
+      .appName("Clustering-Delta")
+      .master("local[*]")
+      .config("spark.sql.extensions", "io.delta.sql.DeltaSparkSessionExtension")
+      .config("spark.sql.catalog.spark_catalog", "org.apache.spark.sql.delta.catalog.DeltaCatalog")
+      .getOrCreate()
+
+    // Clear up old session
+    deltaSpark.sql(s"DROP TABLE IF EXISTS $tableName")
+
+    // Enable preview config for clustering
+    deltaSpark.conf.set(
+      "spark.databricks.delta.clusteredTable.enableClusteringTablePreview", "true")
+
+    try {
+      // Create a table
+      println("Creating a table")
+      deltaSpark.sql(
+        s"""CREATE TABLE $tableName (col1 INT, col2 STRING) using DELTA
+           |CLUSTER BY (col1, col2)""".stripMargin)
+
+      // Insert new data
+      println("Insert new data")
+      deltaSpark.sql(s"INSERT INTO $tableName VALUES (123, '123')")
+
+      // Optimize the table
+      println("Optimize the table")
+      deltaSpark.sql(s"OPTIMIZE $tableName")
+    } finally {
+      // Cleanup
+      deltaSpark.sql(s"DROP TABLE IF EXISTS $tableName")
+      deltaSpark.stop()
+    }
+  }
+}
+