From c079420d7c55d8972db716a2695a5ddd606d11cd Mon Sep 17 00:00:00 2001
From: Cheng Lian <lian@databricks.com>
Date: Sun, 13 Mar 2016 12:02:52 +0800
Subject: [PATCH] [SPARK-13841][SQL] Removes Dataset.collectRows()/takeRows()

## What changes were proposed in this pull request?

This PR removes two methods, `collectRows()` and `takeRows()`, from `Dataset[T]`. These methods were added in PR #11443, and were later considered not useful.

## How was this patch tested?

Existing tests should do the work.

Author: Cheng Lian <lian@databricks.com>

Closes #11678 from liancheng/remove-collect-rows-and-take-rows.
---
 .../examples/ml/JavaBinarizerExample.java     |  2 +-
 .../ml/JavaCrossValidatorExample.java         |  2 +-
 .../examples/ml/JavaDeveloperApiExample.java  |  2 +-
 .../JavaEstimatorTransformerParamExample.java |  3 +-
 ...delSelectionViaCrossValidationExample.java |  2 +-
 .../spark/examples/ml/JavaNGramExample.java   |  2 +-
 .../examples/ml/JavaPipelineExample.java      |  2 +-
 .../ml/JavaPolynomialExpansionExample.java    |  5 ++-
 .../examples/ml/JavaSimpleParamsExample.java  |  3 +-
 .../JavaSimpleTextClassificationPipeline.java |  2 +-
 .../spark/examples/ml/JavaTfIdfExample.java   |  2 +-
 .../examples/ml/JavaTokenizerExample.java     |  2 +-
 .../examples/ml/JavaWord2VecExample.java      |  2 +-
 .../ml/feature/JavaVectorSlicerSuite.java     |  2 +-
 .../org/apache/spark/sql/DataFrame.scala      | 18 ---------
 .../spark/sql/JavaApplySchemaSuite.java       |  4 +-
 .../apache/spark/sql/JavaDataFrameSuite.java  | 39 ++++++++++---------
 17 files changed, 40 insertions(+), 54 deletions(-)

diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaBinarizerExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaBinarizerExample.java
index d554377975..0a6e9c2a1f 100644
--- a/examples/src/main/java/org/apache/spark/examples/ml/JavaBinarizerExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaBinarizerExample.java
@@ -58,7 +58,7 @@ public class JavaBinarizerExample {
       .setThreshold(0.5);
     Dataset<Row> binarizedDataFrame = binarizer.transform(continuousDataFrame);
     Dataset<Row> binarizedFeatures = binarizedDataFrame.select("binarized_feature");
-    for (Row r : binarizedFeatures.collectRows()) {
+    for (Row r : binarizedFeatures.collectAsList()) {
       Double binarized_value = r.getDouble(0);
       System.out.println(binarized_value);
     }
diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaCrossValidatorExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaCrossValidatorExample.java
index 90bc94c45b..07edeb3e52 100644
--- a/examples/src/main/java/org/apache/spark/examples/ml/JavaCrossValidatorExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaCrossValidatorExample.java
@@ -117,7 +117,7 @@ public class JavaCrossValidatorExample {
 
     // Make predictions on test documents. cvModel uses the best model found (lrModel).
     Dataset<Row> predictions = cvModel.transform(test);
-    for (Row r: predictions.select("id", "text", "probability", "prediction").collectRows()) {
+    for (Row r: predictions.select("id", "text", "probability", "prediction").collectAsList()) {
       System.out.println("(" + r.get(0) + ", " + r.get(1) + ") --> prob=" + r.get(2)
           + ", prediction=" + r.get(3));
     }
diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaDeveloperApiExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaDeveloperApiExample.java
index e8ae100d68..8a10dd48aa 100644
--- a/examples/src/main/java/org/apache/spark/examples/ml/JavaDeveloperApiExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaDeveloperApiExample.java
@@ -85,7 +85,7 @@ public class JavaDeveloperApiExample {
     // Make predictions on test documents. cvModel uses the best model found (lrModel).
     Dataset<Row> results = model.transform(test);
     double sumPredictions = 0;
-    for (Row r : results.select("features", "label", "prediction").collectRows()) {
+    for (Row r : results.select("features", "label", "prediction").collectAsList()) {
       sumPredictions += r.getDouble(2);
     }
     if (sumPredictions != 0.0) {
diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaEstimatorTransformerParamExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaEstimatorTransformerParamExample.java
index f13698ae5e..604b193dd4 100644
--- a/examples/src/main/java/org/apache/spark/examples/ml/JavaEstimatorTransformerParamExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaEstimatorTransformerParamExample.java
@@ -100,7 +100,8 @@ public class JavaEstimatorTransformerParamExample {
     // Note that model2.transform() outputs a 'myProbability' column instead of the usual
     // 'probability' column since we renamed the lr.probabilityCol parameter previously.
     Dataset<Row> results = model2.transform(test);
-    for (Row r : results.select("features", "label", "myProbability", "prediction").collectRows()) {
+    Dataset<Row> rows = results.select("features", "label", "myProbability", "prediction");
+    for (Row r: rows.collectAsList()) {
       System.out.println("(" + r.get(0) + ", " + r.get(1) + ") -> prob=" + r.get(2)
         + ", prediction=" + r.get(3));
     }
diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaModelSelectionViaCrossValidationExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaModelSelectionViaCrossValidationExample.java
index e394605db7..c4122d1247 100644
--- a/examples/src/main/java/org/apache/spark/examples/ml/JavaModelSelectionViaCrossValidationExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaModelSelectionViaCrossValidationExample.java
@@ -111,7 +111,7 @@ public class JavaModelSelectionViaCrossValidationExample {
 
     // Make predictions on test documents. cvModel uses the best model found (lrModel).
     Dataset<Row> predictions = cvModel.transform(test);
-    for (Row r : predictions.select("id", "text", "probability", "prediction").collectRows()) {
+    for (Row r : predictions.select("id", "text", "probability", "prediction").collectAsList()) {
       System.out.println("(" + r.get(0) + ", " + r.get(1) + ") --> prob=" + r.get(2)
         + ", prediction=" + r.get(3));
     }
diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaNGramExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaNGramExample.java
index 0305f737ca..608bd80285 100644
--- a/examples/src/main/java/org/apache/spark/examples/ml/JavaNGramExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaNGramExample.java
@@ -60,7 +60,7 @@ public class JavaNGramExample {
 
     Dataset<Row> ngramDataFrame = ngramTransformer.transform(wordDataFrame);
 
-    for (Row r : ngramDataFrame.select("ngrams", "label").takeRows(3)) {
+    for (Row r : ngramDataFrame.select("ngrams", "label").takeAsList(3)) {
       java.util.List<String> ngrams = r.getList(0);
       for (String ngram : ngrams) System.out.print(ngram + " --- ");
       System.out.println();
diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaPipelineExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaPipelineExample.java
index 6ae418d564..305420f208 100644
--- a/examples/src/main/java/org/apache/spark/examples/ml/JavaPipelineExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaPipelineExample.java
@@ -80,7 +80,7 @@ public class JavaPipelineExample {
 
     // Make predictions on test documents.
     Dataset<Row> predictions = model.transform(test);
-    for (Row r : predictions.select("id", "text", "probability", "prediction").collectRows()) {
+    for (Row r : predictions.select("id", "text", "probability", "prediction").collectAsList()) {
       System.out.println("(" + r.get(0) + ", " + r.get(1) + ") --> prob=" + r.get(2)
         + ", prediction=" + r.get(3));
     }
diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaPolynomialExpansionExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaPolynomialExpansionExample.java
index 5a4064c604..48fc3c8acb 100644
--- a/examples/src/main/java/org/apache/spark/examples/ml/JavaPolynomialExpansionExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaPolynomialExpansionExample.java
@@ -23,6 +23,7 @@ import org.apache.spark.sql.SQLContext;
 
 // $example on$
 import java.util.Arrays;
+import java.util.List;
 
 import org.apache.spark.api.java.JavaRDD;
 import org.apache.spark.ml.feature.PolynomialExpansion;
@@ -61,8 +62,8 @@ public class JavaPolynomialExpansionExample {
     Dataset<Row> df = jsql.createDataFrame(data, schema);
     Dataset<Row> polyDF = polyExpansion.transform(df);
 
-    Row[] row = polyDF.select("polyFeatures").takeRows(3);
-    for (Row r : row) {
+    List<Row> rows = polyDF.select("polyFeatures").takeAsList(3);
+    for (Row r : rows) {
       System.out.println(r.get(0));
     }
     // $example off$
diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaSimpleParamsExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaSimpleParamsExample.java
index 52bb4ec050..cb911ef5ef 100644
--- a/examples/src/main/java/org/apache/spark/examples/ml/JavaSimpleParamsExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaSimpleParamsExample.java
@@ -103,7 +103,8 @@ public class JavaSimpleParamsExample {
     // Note that model2.transform() outputs a 'myProbability' column instead of the usual
     // 'probability' column since we renamed the lr.probabilityCol parameter previously.
     Dataset<Row> results = model2.transform(test);
-    for (Row r: results.select("features", "label", "myProbability", "prediction").collectRows()) {
+    Dataset<Row> rows = results.select("features", "label", "myProbability", "prediction");
+    for (Row r: rows.collectAsList()) {
       System.out.println("(" + r.get(0) + ", " + r.get(1) + ") -> prob=" + r.get(2)
           + ", prediction=" + r.get(3));
     }
diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaSimpleTextClassificationPipeline.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaSimpleTextClassificationPipeline.java
index 9bd543c44f..a18a60f448 100644
--- a/examples/src/main/java/org/apache/spark/examples/ml/JavaSimpleTextClassificationPipeline.java
+++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaSimpleTextClassificationPipeline.java
@@ -84,7 +84,7 @@ public class JavaSimpleTextClassificationPipeline {
 
     // Make predictions on test documents.
     Dataset<Row> predictions = model.transform(test);
-    for (Row r: predictions.select("id", "text", "probability", "prediction").collectRows()) {
+    for (Row r: predictions.select("id", "text", "probability", "prediction").collectAsList()) {
       System.out.println("(" + r.get(0) + ", " + r.get(1) + ") --> prob=" + r.get(2)
           + ", prediction=" + r.get(3));
     }
diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaTfIdfExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaTfIdfExample.java
index fd1ce424bf..37a3d0d84d 100644
--- a/examples/src/main/java/org/apache/spark/examples/ml/JavaTfIdfExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaTfIdfExample.java
@@ -66,7 +66,7 @@ public class JavaTfIdfExample {
     IDF idf = new IDF().setInputCol("rawFeatures").setOutputCol("features");
     IDFModel idfModel = idf.fit(featurizedData);
     Dataset<Row> rescaledData = idfModel.transform(featurizedData);
-    for (Row r : rescaledData.select("features", "label").takeRows(3)) {
+    for (Row r : rescaledData.select("features", "label").takeAsList(3)) {
       Vector features = r.getAs(0);
       Double label = r.getDouble(1);
       System.out.println(features);
diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaTokenizerExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaTokenizerExample.java
index a2f8c436e3..9225fe2262 100644
--- a/examples/src/main/java/org/apache/spark/examples/ml/JavaTokenizerExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaTokenizerExample.java
@@ -59,7 +59,7 @@ public class JavaTokenizerExample {
     Tokenizer tokenizer = new Tokenizer().setInputCol("sentence").setOutputCol("words");
 
     Dataset<Row> wordsDataFrame = tokenizer.transform(sentenceDataFrame);
-    for (Row r : wordsDataFrame.select("words", "label").takeRows(3)) {
+    for (Row r : wordsDataFrame.select("words", "label").takeAsList(3)) {
       java.util.List<String> words = r.getList(0);
       for (String word : words) System.out.print(word + " ");
       System.out.println();
diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaWord2VecExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaWord2VecExample.java
index 2dce8c2168..c5bb1eaaa3 100644
--- a/examples/src/main/java/org/apache/spark/examples/ml/JavaWord2VecExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaWord2VecExample.java
@@ -59,7 +59,7 @@ public class JavaWord2VecExample {
       .setMinCount(0);
     Word2VecModel model = word2Vec.fit(documentDF);
     Dataset<Row> result = model.transform(documentDF);
-    for (Row r : result.select("result").takeRows(3)) {
+    for (Row r : result.select("result").takeAsList(3)) {
       System.out.println(r);
     }
     // $example off$
diff --git a/mllib/src/test/java/org/apache/spark/ml/feature/JavaVectorSlicerSuite.java b/mllib/src/test/java/org/apache/spark/ml/feature/JavaVectorSlicerSuite.java
index b87605ebfd..e2da11183b 100644
--- a/mllib/src/test/java/org/apache/spark/ml/feature/JavaVectorSlicerSuite.java
+++ b/mllib/src/test/java/org/apache/spark/ml/feature/JavaVectorSlicerSuite.java
@@ -78,7 +78,7 @@ public class JavaVectorSlicerSuite {
 
     Dataset<Row> output = vectorSlicer.transform(dataset);
 
-    for (Row r : output.select("userFeatures", "features").takeRows(2)) {
+    for (Row r : output.select("userFeatures", "features").takeAsList(2)) {
       Vector features = r.getAs(1);
       Assert.assertEquals(features.size(), 2);
     }
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala b/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala
index f1791e6943..1ea7db0388 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala
@@ -1762,10 +1762,6 @@ class Dataset[T] private[sql](
    */
   def take(n: Int): Array[T] = head(n)
 
-  def takeRows(n: Int): Array[Row] = withTypedCallback("takeRows", limit(n)) { ds =>
-    ds.collectRows(needCallback = false)
-  }
-
   /**
    * Returns the first `n` rows in the [[DataFrame]] as a list.
    *
@@ -1790,8 +1786,6 @@ class Dataset[T] private[sql](
    */
   def collect(): Array[T] = collect(needCallback = true)
 
-  def collectRows(): Array[Row] = collectRows(needCallback = true)
-
   /**
    * Returns a Java list that contains all of [[Row]]s in this [[DataFrame]].
    *
@@ -1820,18 +1814,6 @@ class Dataset[T] private[sql](
     }
   }
 
-  private def collectRows(needCallback: Boolean): Array[Row] = {
-    def execute(): Array[Row] = withNewExecutionId {
-      queryExecution.executedPlan.executeCollectPublic()
-    }
-
-    if (needCallback) {
-      withCallback("collect", toDF())(_ => execute())
-    } else {
-      execute()
-    }
-  }
-
   /**
    * Returns the number of rows in the [[DataFrame]].
    * @group action
diff --git a/sql/core/src/test/java/test/org/apache/spark/sql/JavaApplySchemaSuite.java b/sql/core/src/test/java/test/org/apache/spark/sql/JavaApplySchemaSuite.java
index 42af813bc1..ae9c8cc1ba 100644
--- a/sql/core/src/test/java/test/org/apache/spark/sql/JavaApplySchemaSuite.java
+++ b/sql/core/src/test/java/test/org/apache/spark/sql/JavaApplySchemaSuite.java
@@ -109,13 +109,13 @@ public class JavaApplySchemaSuite implements Serializable {
 
     Dataset<Row> df = sqlContext.createDataFrame(rowRDD, schema);
     df.registerTempTable("people");
-    Row[] actual = sqlContext.sql("SELECT * FROM people").collectRows();
+    List<Row> actual = sqlContext.sql("SELECT * FROM people").collectAsList();
 
     List<Row> expected = new ArrayList<>(2);
     expected.add(RowFactory.create("Michael", 29));
     expected.add(RowFactory.create("Yin", 28));
 
-    Assert.assertEquals(expected, Arrays.asList(actual));
+    Assert.assertEquals(expected, actual);
   }
 
   @Test
diff --git a/sql/core/src/test/java/test/org/apache/spark/sql/JavaDataFrameSuite.java b/sql/core/src/test/java/test/org/apache/spark/sql/JavaDataFrameSuite.java
index 47cc74dbc1..42554720ed 100644
--- a/sql/core/src/test/java/test/org/apache/spark/sql/JavaDataFrameSuite.java
+++ b/sql/core/src/test/java/test/org/apache/spark/sql/JavaDataFrameSuite.java
@@ -19,6 +19,7 @@ package test.org.apache.spark.sql;
 
 import java.io.Serializable;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
@@ -65,7 +66,7 @@ public class JavaDataFrameSuite {
   @Test
   public void testExecution() {
     Dataset<Row> df = context.table("testData").filter("key = 1");
-    Assert.assertEquals(1, df.select("key").collectRows()[0].get(0));
+    Assert.assertEquals(1, df.select("key").collectAsList().get(0).get(0));
   }
 
   @Test
@@ -208,8 +209,8 @@ public class JavaDataFrameSuite {
     StructType schema = createStructType(Arrays.asList(createStructField("i", IntegerType, true)));
     List<Row> rows = Arrays.asList(RowFactory.create(0));
     Dataset<Row> df = context.createDataFrame(rows, schema);
-    Row[] result = df.collectRows();
-    Assert.assertEquals(1, result.length);
+    List<Row> result = df.collectAsList();
+    Assert.assertEquals(1, result.size());
   }
 
   @Test
@@ -241,8 +242,8 @@ public class JavaDataFrameSuite {
     Assert.assertEquals("a_b", columnNames[0]);
     Assert.assertEquals("2", columnNames[1]);
     Assert.assertEquals("1", columnNames[2]);
-    Row[] rows = crosstab.collectRows();
-    Arrays.sort(rows, crosstabRowComparator);
+    List<Row> rows = crosstab.collectAsList();
+    Collections.sort(rows, crosstabRowComparator);
     Integer count = 1;
     for (Row row : rows) {
       Assert.assertEquals(row.get(0).toString(), count.toString());
@@ -257,7 +258,7 @@ public class JavaDataFrameSuite {
     Dataset<Row> df = context.table("testData2");
     String[] cols = {"a"};
     Dataset<Row> results = df.stat().freqItems(cols, 0.2);
-    Assert.assertTrue(results.collectRows()[0].getSeq(0).contains(1));
+    Assert.assertTrue(results.collectAsList().get(0).getSeq(0).contains(1));
   }
 
   @Test
@@ -278,27 +279,27 @@ public class JavaDataFrameSuite {
   public void testSampleBy() {
     Dataset<Row> df = context.range(0, 100, 1, 2).select(col("id").mod(3).as("key"));
     Dataset<Row> sampled = df.stat().<Integer>sampleBy("key", ImmutableMap.of(0, 0.1, 1, 0.2), 0L);
-    Row[] actual = sampled.groupBy("key").count().orderBy("key").collectRows();
-    Assert.assertEquals(0, actual[0].getLong(0));
-    Assert.assertTrue(0 <= actual[0].getLong(1) && actual[0].getLong(1) <= 8);
-    Assert.assertEquals(1, actual[1].getLong(0));
-    Assert.assertTrue(2 <= actual[1].getLong(1) && actual[1].getLong(1) <= 13);
+    List<Row> actual = sampled.groupBy("key").count().orderBy("key").collectAsList();
+    Assert.assertEquals(0, actual.get(0).getLong(0));
+    Assert.assertTrue(0 <= actual.get(0).getLong(1) && actual.get(0).getLong(1) <= 8);
+    Assert.assertEquals(1, actual.get(1).getLong(0));
+    Assert.assertTrue(2 <= actual.get(1).getLong(1) && actual.get(1).getLong(1) <= 13);
   }
 
   @Test
   public void pivot() {
     Dataset<Row> df = context.table("courseSales");
-    Row[] actual = df.groupBy("year")
+    List<Row> actual = df.groupBy("year")
       .pivot("course", Arrays.<Object>asList("dotNET", "Java"))
-      .agg(sum("earnings")).orderBy("year").collectRows();
+      .agg(sum("earnings")).orderBy("year").collectAsList();
 
-    Assert.assertEquals(2012, actual[0].getInt(0));
-    Assert.assertEquals(15000.0, actual[0].getDouble(1), 0.01);
-    Assert.assertEquals(20000.0, actual[0].getDouble(2), 0.01);
+    Assert.assertEquals(2012, actual.get(0).getInt(0));
+    Assert.assertEquals(15000.0, actual.get(0).getDouble(1), 0.01);
+    Assert.assertEquals(20000.0, actual.get(0).getDouble(2), 0.01);
 
-    Assert.assertEquals(2013, actual[1].getInt(0));
-    Assert.assertEquals(48000.0, actual[1].getDouble(1), 0.01);
-    Assert.assertEquals(30000.0, actual[1].getDouble(2), 0.01);
+    Assert.assertEquals(2013, actual.get(1).getInt(0));
+    Assert.assertEquals(48000.0, actual.get(1).getDouble(1), 0.01);
+    Assert.assertEquals(30000.0, actual.get(1).getDouble(2), 0.01);
   }
 
   @Test
-- 
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